Variation of radio frequency and ultrasonic power level in cooperation with varying clamp arm pressure to achieve predefined heat flux or power applied to tissue

ABSTRACT

Surgical instruments and system and methods for using surgical instruments are disclosed. A surgical instrument comprises an end effector comprising an ultrasonic blade and clamp arm, an electrode, an ultrasonic transducer, and a sensor coupled to a control circuit. The electrode receives electrosurgical energy from a generator and applies the electrosurgical energy to the end effector to weld tissue based on the generator generating a drive signal. The ultrasonic transducer ultrasonically oscillates the ultrasonic blade in response to the drive signal. The control circuit receives a signal from the sensor indicative of a surgical parameter, determines a weld time of a surgical operation based on the sensor signal, and varies one or more of a clamp arm pressure applied by the clamp arm and a power level of the electrosurgical energy to maintain one or more of a predefined heat flux or power applied to tissue loaded in the end effector.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/729,195, titled ULTRASONIC ENERGY DEVICE WHICH VARIES PRESSURE APPLIED BY CLAMP ARM TO PROVIDE THRESHOLD CONTROL PRESSURE ATA CUT PROGRESSION LOCATION, filed on Sep. 10, 2018, the disclosure of which is herein incorporated by reference in its entirety.

The present application also claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/692,747, titled SMART ACTIVATION OF AN ENERGY DEVICE BY ANOTHER DEVICE, filed on Jun. 30, 2018, to U.S. Provisional Patent Application No. 62/692,748, titled SMART ENERGY ARCHITECTURE, filed on Jun. 30, 2018, and to U.S. Provisional Patent Application No. 62/692,768, titled SMART ENERGY DEVICES, filed on Jun. 30, 2018, the disclosure of each of which is herein incorporated by reference in its entirety.

The present application also claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/659,900, titled METHOD OF HUB COMMUNICATION, filed on Apr. 19, 2018, the disclosure of each of which is herein incorporated by reference in its entirety.

The present application also claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 62/650,898 filed on Mar. 30, 2018, titled CAPACITIVE COUPLED RETURN PATH PAD WITH SEPARABLE ARRAY ELEMENTS, to U.S. Provisional Patent Application Ser. No. 62/650,887, titled SURGICAL SYSTEMS WITH OPTIMIZED SENSING CAPABILITIES, filed Mar. 30, 2018, to U.S. Provisional Patent Application Ser. No. 62/650,882, titled SMOKE EVACUATION MODULE FOR INTERACTIVE SURGICAL PLATFORM, filed Mar. 30, 2018, and to U.S. Provisional Patent Application Ser. No. 62/650,877, titled SURGICAL SMOKE EVACUATION SENSING AND CONTROLS, filed Mar. 30, 2018, the disclosure of each of which is herein incorporated by reference in its entirety.

The present application also claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 62/640,417, titled TEMPERATURE CONTROL IN ULTRASONIC DEVICE AND CONTROL SYSTEM THEREFOR, filed Mar. 8, 2018, and to U.S. Provisional Patent Application Ser. No. 62/640,415, titled ESTIMATING STATE OF ULTRASONIC END EFFECTOR AND CONTROL SYSTEM THEREFOR, filed Mar. 8, 2018, the disclosure of each of which is herein incorporated by reference in its entirety.

The present application also claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, to U.S. Provisional Patent Application Ser. No. 62/611,340, titled CLOUD-BASED MEDICAL ANALYTICS, filed Dec. 28, 2017, and to U.S. Provisional Patent Application Ser. No. 62/611,339, titled ROBOT ASSISTED SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of each of which is herein incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates to various surgical systems. Surgical procedures are typically performed in surgical operating theaters or rooms in a healthcare facility such as, for example, a hospital. A sterile field is typically created around the patient. The sterile field may include the scrubbed team members, who are properly attired, and all furniture and fixtures in the area. Various surgical devices and systems are utilized in performance of a surgical procedure.

FIGURES

The various aspects described herein, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings as follows.

FIG. 1 is a block diagram of a computer-implemented interactive surgical system, in accordance with at least one aspect of the present disclosure.

FIG. 2 is a surgical system being used to perform a surgical procedure in an operating room, in accordance with at least one aspect of the present disclosure.

FIG. 3 is a surgical hub paired with a visualization system, a robotic system, and an intelligent instrument, in accordance with at least one aspect of the present disclosure.

FIG. 4 is a partial perspective view of a surgical hub enclosure, and of a combo generator module slidably receivable in a drawer of the surgical hub enclosure, in accordance with at least one aspect of the present disclosure.

FIG. 5 is a perspective view of a combo generator module with bipolar, ultrasonic, and monopolar contacts and a smoke evacuation component, in accordance with at least one aspect of the present disclosure.

FIG. 6 illustrates individual power bus attachments for a plurality of lateral docking ports of a lateral modular housing configured to receive a plurality of modules, in accordance with at least one aspect of the present disclosure.

FIG. 7 illustrates a vertical modular housing configured to receive a plurality of modules, in accordance with at least one aspect of the present disclosure.

FIG. 8 illustrates a surgical data network comprising a modular communication hub configured to connect modular devices located in one or more operating theaters of a healthcare facility, or any room in a healthcare facility specially equipped for surgical operations, to the cloud, in accordance with at least one aspect of the present disclosure.

FIG. 9 illustrates a computer-implemented interactive surgical system, in accordance with at least one aspect of the present disclosure.

FIG. 10 illustrates a surgical hub comprising a plurality of modules coupled to the modular control tower, in accordance with at least one aspect of the present disclosure.

FIG. 11 illustrates one aspect of a Universal Serial Bus (USB) network hub device, in accordance with at least one aspect of the present disclosure.

FIG. 12 is a block diagram of a cloud computing system comprising a plurality of smart surgical instruments coupled to surgical hubs that may connect to the cloud component of the cloud computing system, in accordance with at least one aspect of the present disclosure.

FIG. 13 is a functional module architecture of a cloud computing system, in accordance with at least one aspect of the present disclosure.

FIG. 14 illustrates a diagram of a situationally aware surgical system, in accordance with at least one aspect of the present disclosure.

FIG. 15 is a timeline depicting situational awareness of a surgical hub, in accordance with at least one aspect of the present disclosure.

FIG. 16 is a schematic diagram of a robotic surgical instrument configured to operate a surgical tool described herein, in accordance with at least one aspect of the present disclosure.

FIG. 17 illustrates a block diagram of a surgical instrument programmed to control the distal translation of a displacement member, in accordance with at least one aspect of the present disclosure.

FIG. 18 is a schematic diagram of a surgical instrument configured to control various functions, in accordance with at least one aspect of the present disclosure.

FIG. 19 illustrates an example of a generator, in accordance with at least one aspect of the present disclosure.

FIG. 20 is a structural view of a generator architecture, in accordance with at least one aspect of the present disclosure.

FIG. 21 illustrates a generator circuit partitioned into multiple stages where a first stage circuit is common to the second stage circuit, in accordance with at least one aspect of the present disclosure.

FIG. 22 illustrates a diagram of one aspect of a surgical instrument comprising a feedback system for use with a surgical instrument, according to one aspect of the present disclosure.

FIGS. 23A-23B are graphs including a graph of clamp force as a function of time and an associated graph indicating the shift in the location of coagulation and cutting along the length of the blade as a function time, in accordance with at least one aspect of the present disclosure.

FIGS. 24A-24B depict segments of end effector electrodes and an illustration of controlling applied clamp force and delivered electrosurgical energy by the end effector, in accordance with at least one aspect of the present disclosure.

FIGS. 25A-25B are graphs illustrating controlling the energization or powering of the electrosurgical electrodes, in accordance with at least one aspect of the present disclosure.

FIGS. 26A-26E are a series of graphs illustrating the adjustment of power level to achieve a predictable sealing time, in accordance with at least one aspect of the present disclosure.

FIGS. 27A-27F are graphs and flow charts illustrating approaches to delivering energy according to power curves, in accordance with at least one aspect of the present disclosure.

DESCRIPTION

Applicant of the present application owns the following U.S. Patent Applications, filed on Nov. 6, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. patent application Ser. No. 16/182,224, titled SURGICAL         NETWORK, INSTRUMENT, AND CLOUD RESPONSES BASED ON VALIDATION OF         RECEIVED DATASET AND AUTHENTICATION OF ITS SOURCE AND INTEGRITY,         now U.S. Pat. No. 11,308,075;     -   U.S. patent application Ser. No. 16/182,230, titled SURGICAL         SYSTEM FOR PRESENTING INFORMATION INTERPRETED FROM EXTERNAL         DATA, now U.S. Patent Application Publication No. 2019/0200980;     -   U.S. patent application Ser. No. 16/182,233, titled SURGICAL         SYSTEMS WITH AUTONOMOUSLY ADJUSTABLE CONTROL PROGRAMS, now U.S.         Patent Application Publication No. 2019/0201123;     -   U.S. patent application Ser. No. 16/182,239, titled ADJUSTMENT         OF DEVICE CONTROL PROGRAMS BASED ON STRATIFIED CONTEXTUAL DATA         IN ADDITION TO THE DATA, now U.S. Patent Application Publication         No. 2019/0201124;     -   U.S. patent application Ser. No. 16/182,243, titled SURGICAL HUB         AND MODULAR DEVICE RESPONSE ADJUSTMENT BASED ON SITUATIONAL         AWARENESS, now U.S. Pat. No. 11,273,001;     -   U.S. patent application Ser. No. 16/182,248, titled DETECTION         AND ESCALATION OF SECURITY RESPONSES OF SURGICAL INSTRUMENTS TO         INCREASING SEVERITY THREATS, now U.S. Pat. No. 10,943,454;     -   U.S. patent application Ser. No. 16/182,251, titled INTERACTIVE         SURGICAL SYSTEM, now U.S. Pat. No. 11,278,281;     -   U.S. patent application Ser. No. 16/182,260, titled AUTOMATED         DATA SCALING, ALIGNMENT, AND ORGANIZING BASED ON PREDEFINED         PARAMETERS WITHIN SURGICAL NETWORKS, now U.S. Pat. No.         11,056,244;     -   U.S. patent application Ser. No. 16/182,267, titled SENSING THE         PATIENT POSITION AND CONTACT UTILIZING THE MONO-POLAR RETURN PAD         ELECTRODE TO PROVIDE SITUATIONAL AWARENESS TO THE HUB, now U.S.         Patent Application Publication No. 2019/0201128;     -   U.S. patent application Ser. No. 16/182,249, titled POWERED         SURGICAL TOOL WITH PREDEFINED ADJUSTABLE CONTROL ALGORITHM FOR         CONTROLLING END EFFECTOR PARAMETER, now U.S. Pat. No.         11,234,756;     -   U.S. patent application Ser. No. 16/182,246, titled ADJUSTMENTS         BASED ON AIRBORNE PARTICLE PROPERTIES, now U.S. Patent         Application Publication No. 2019/0204201;     -   U.S. patent application Ser. No. 16/182,256, titled ADJUSTMENT         OF A SURGICAL DEVICE FUNCTION BASED ON SITUATIONAL AWARENESS,         now U.S. Patent Application Publication No. 2019/0201127;     -   U.S. patent application Ser. No. 16/182,242, titled REAL-TIME         ANALYSIS OF COMPREHENSIVE COST OF ALL INSTRUMENTATION USED IN         SURGERY UTILIZING DATA FLUIDITY TO TRACK INSTRUMENTS THROUGH         STOCKING AND IN-HOUSE PROCESSES, now U.S. Pat. No. 11,257,589;     -   U.S. patent application Ser. No. 16/182,255, titled USAGE AND         TECHNIQUE ANALYSIS OF SURGEON/STAFF PERFORMANCE AGAINST A         BASELINE TO OPTIMIZE DEVICE UTILIZATION AND PERFORMANCE FOR BOTH         CURRENT AND FUTURE PROCEDURES, now U.S. Patent Application         Publication No. 2019/0201126;     -   U.S. patent application Ser. No. 16/182,269, titled IMAGE         CAPTURING OF THE AREAS OUTSIDE THE ABDOMEN TO IMPROVE PLACEMENT         AND CONTROL OF A SURGICAL DEVICE IN USE, now U.S. Pat. No.         11,304,763;     -   U.S. patent application Ser. No. 16/182,278, titled         COMMUNICATION OF DATA WHERE A SURGICAL NETWORK IS USING CONTEXT         OF THE DATA AND REQUIREMENTS OF A RECEIVING SYSTEM/USER TO         INFLUENCE INCLUSION OR LINKAGE OF DATA AND METADATA TO ESTABLISH         CONTINUITY, now U.S. Patent Application Publication No.         2019/0201130;     -   U.S. patent application Ser. No. 16/182,290, titled SURGICAL         NETWORK RECOMMENDATIONS FROM REAL TIME ANALYSIS OF PROCEDURE         VARIABLES AGAINST A BASELINE HIGHLIGHTING DIFFERENCES FROM THE         OPTIMAL SOLUTION, now U.S. Patent Application Publication No.         2019,0201102;     -   U.S. patent application Ser. No. 16/182,232, titled CONTROL OF A         SURGICAL SYSTEM THROUGH A SURGICAL BARRIER, now U.S. Patent         Application Publication No. 2019/0201158;     -   U.S. patent application Ser. No. 16/182,227, titled SURGICAL         NETWORK DETERMINATION OF PRIORITIZATION OF COMMUNICATION,         INTERACTION, OR PROCESSING BASED ON SYSTEM OR DEVICE NEEDS, now         U.S. Pat. No. 10,892,995;     -   U.S. patent application Ser. No. 16/182,231, titled WIRELESS         PAIRING OF A SURGICAL DEVICE WITH ANOTHER DEVICE WITHIN A         STERILE SURGICAL FIELD BASED ON THE USAGE AND SITUATIONAL         AWARENESS OF DEVICES, now U.S. Pat. No. 10,758,310;     -   U.S. patent application Ser. No. 16/182,229, titled ADJUSTMENT         OF STAPLE HEIGHT OF AT LEAST ONE ROW OF STAPLES BASED ON THE         SENSED TISSUE THICKNESS OR FORCE IN CLOSING, now U.S. Pat. No.         11,096,693;     -   U.S. patent application Ser. No. 16/182,234, titled STAPLING         DEVICE WITH BOTH COMPULSORY AND DISCRETIONARY LOCKOUTS BASED ON         SENSED PARAMETERS, now U.S. Patent Application Publication No.         2019/0200997;     -   U.S. patent application Ser. No. 16/182,240, titled POWERED         STAPLING DEVICE CONFIGURED TO ADJUST FORCE, ADVANCEMENT SPEED,         AND OVERALL STROKE OF CUTTING MEMBER BASED ON SENSED PARAMETER         OF FIRING OR CLAMPING, now U.S. Patent Application Publication         No. 2019/0201034; and     -   U.S. patent application Ser. No. 16/182,238, titled ULTRASONIC         ENERGY DEVICE WHICH VARIES PRESSURE APPLIED BY CLAMP ARM TO         PROVIDE THRESHOLD CONTROL PRESSURE AT A CUT PROGRESSION         LOCATION, now U.S. Patent Application Publication No.         2019/0201080.

Applicant of the present application owns the following U.S. Patent Applications, filed on Sep. 10, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application No. 62/729,183, titled A         CONTROL FOR A SURGICAL NETWORK OR SURGICAL NETWORK CONNECTED         DEVICE THAT ADJUSTS ITS FUNCTION BASED ON A SENSED SITUATION OR         USAGE;     -   U.S. Provisional Patent Application No. 62/729,177, titled         AUTOMATED DATA SCALING, ALIGNMENT, AND ORGANIZING BASED ON         PREDEFINED PARAMETERS WITHIN A SURGICAL NETWORK BEFORE         TRANSMISSION;     -   U.S. Provisional Patent Application No. 62/729,176, titled         INDIRECT COMMAND AND CONTROL OF A FIRST OPERATING ROOM SYSTEM         THROUGH THE USE OF A SECOND OPERATING ROOM SYSTEM WITHIN A         STERILE FIELD WHERE THE SECOND OPERATING ROOM SYSTEM HAS PRIMARY         AND SECONDARY OPERATING MODES;     -   U.S. Provisional Patent Application No. 62/729,185, titled         POWERED STAPLING DEVICE THAT IS CAPABLE OF ADJUSTING FORCE,         ADVANCEMENT SPEED, AND OVERALL STROKE OF CUTTING MEMBER OF THE         DEVICE BASED ON SENSED PARAMETER OF FIRING OR CLAMPING;     -   U.S. Provisional Patent Application No. 62/729,184, titled         POWERED SURGICAL TOOL WITH A PREDEFINED ADJUSTABLE CONTROL         ALGORITHM FOR CONTROLLING AT LEAST ONE END EFFECTOR PARAMETER         AND A MEANS FOR LIMITING THE ADJUSTMENT;     -   U.S. Provisional Patent Application No. 62/729,182, titled         SENSING THE PATIENT POSITION AND CONTACT UTILIZING THE MONO         POLAR RETURN PAD ELECTRODE TO PROVIDE SITUATIONAL AWARENESS TO         THE HUB;     -   U.S. Provisional Patent Application No. 62/729,191, titled         SURGICAL NETWORK RECOMMENDATIONS FROM REAL TIME ANALYSIS OF         PROCEDURE VARIABLES AGAINST A BASELINE HIGHLIGHTING DIFFERENCES         FROM THE OPTIMAL SOLUTION;     -   U.S. Provisional Patent Application No. 62/729,195, titled         ULTRASONIC ENERGY DEVICE WHICH VARIES PRESSURE APPLIED BY CLAMP         ARM TO PROVIDE THRESHOLD CONTROL PRESSURE AT A CUT PROGRESSION         LOCATION; and     -   U.S. Provisional Patent Application No. 62/729,186, titled         WIRELESS PAIRING OF A SURGICAL DEVICE WITH ANOTHER DEVICE WITHIN         A STERILE SURGICAL FIELD BASED ON THE USAGE AND SITUATIONAL         AWARENESS OF DEVICES.

Applicant of the present application owns the following U.S. Patent Applications, filed on Aug. 28, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. patent application Ser. No. 16/115,214, titled ESTIMATING         STATE OF ULTRASONIC END EFFECTOR AND CONTROL SYSTEM THEREFOR;     -   U.S. patent application Ser. No. 16/115,205, titled TEMPERATURE         CONTROL OF ULTRASONIC END EFFECTOR AND CONTROL SYSTEM THEREFOR;     -   U.S. patent application Ser. No. 16/115,233, titled RADIO         FREQUENCY ENERGY DEVICE FOR DELIVERING COMBINED ELECTRICAL         SIGNALS;     -   U.S. patent application Ser. No. 16/115,208, titled CONTROLLING         AN ULTRASONIC SURGICAL INSTRUMENT ACCORDING TO TISSUE LOCATION;     -   U.S. patent application Ser. No. 16/115,220, titled CONTROLLING         ACTIVATION OF AN ULTRASONIC SURGICAL INSTRUMENT ACCORDING TO THE         PRESENCE OF TISSUE;     -   U.S. patent application Ser. No. 16/115,232, titled DETERMINING         TISSUE COMPOSITION VIA AN ULTRASONIC SYSTEM;     -   U.S. patent application Ser. No. 16/115,239, titled DETERMINING         THE STATE OF AN ULTRASONIC ELECTROMECHANICAL SYSTEM ACCORDING TO         FREQUENCY SHIFT;     -   U.S. patent application Ser. No. 16/115,247, titled DETERMINING         THE STATE OF AN ULTRASONIC END EFFECTOR;     -   U.S. patent application Ser. No. 16/115,211, titled SITUATIONAL         AWARENESS OF ELECTROSURGICAL SYSTEMS;     -   U.S. patent application Ser. No. 16/115,226, titled MECHANISMS         FOR CONTROLLING DIFFERENT ELECTROMECHANICAL SYSTEMS OF AN         ELECTROSURGICAL INSTRUMENT;     -   U.S. patent application Ser. No. 16/115,240, titled DETECTION OF         END EFFECTOR IMMERSION IN LIQUID;     -   U.S. patent application Ser. No. 16/115,249, titled INTERRUPTION         OF ENERGY DUE TO INADVERTENT CAPACITIVE COUPLING;     -   U.S. patent application Ser. No. 16/115,256, titled INCREASING         RADIO FREQUENCY TO CREATE PAD-LESS MONOPOLAR LOOP;     -   U.S. patent application Ser. No. 16/115,223, titled BIPOLAR         COMBINATION DEVICE THAT AUTOMATICALLY ADJUSTS PRESSURE BASED ON         ENERGY MODALITY; and     -   U.S. patent application Ser. No. 16/115,238, titled ACTIVATION         OF ENERGY DEVICES.

Applicant of the present application owns the following U.S. Patent Applications, filed on Aug. 23, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application No. 62/721,995, titled         CONTROLLING AN ULTRASONIC SURGICAL INSTRUMENT ACCORDING TO         TISSUE LOCATION;     -   U.S. Provisional Patent Application No. 62/721,998, titled         SITUATIONAL AWARENESS OF ELECTROSURGICAL SYSTEMS;     -   U.S. Provisional Patent Application No. 62/721,999, titled         INTERRUPTION OF ENERGY DUE TO INADVERTENT CAPACITIVE COUPLING;     -   U.S. Provisional Patent Application No. 62/721,994, titled         BIPOLAR COMBINATION DEVICE THAT AUTOMATICALLY ADJUSTS PRESSURE         BASED ON ENERGY MODALITY; and     -   U.S. Provisional Patent Application No. 62/721,996, titled RADIO         FREQUENCY ENERGY DEVICE FOR DELIVERING COMBINED ELECTRICAL         SIGNALS.

Applicant of the present application owns the following U.S. Patent Applications, filed on Jun. 30, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application No. 62/692,747, titled SMART         ACTIVATION OF AN ENERGY DEVICE BY ANOTHER DEVICE;     -   U.S. Provisional Patent Application No. 62/692,748, titled SMART         ENERGY ARCHITECTURE; and     -   U.S. Provisional Patent Application No. 62/692,768, titled SMART         ENERGY DEVICES.

Applicant of the present application owns the following U.S. Patent Applications, filed on Jun. 29, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. patent application Ser. No. 16/024,090, titled CAPACITIVE         COUPLED RETURN PATH PAD WITH SEPARABLE ARRAY ELEMENTS;     -   U.S. patent application Ser. No. 16/024,057, titled CONTROLLING         A SURGICAL INSTRUMENT ACCORDING TO SENSED CLOSURE PARAMETERS;     -   U.S. patent application Ser. No. 16/024,067, titled SYSTEMS FOR         ADJUSTING END EFFECTOR PARAMETERS BASED ON PERIOPERATIVE         INFORMATION;     -   U.S. patent application Ser. No. 16/024,075, titled SAFETY         SYSTEMS FOR SMART POWERED SURGICAL STAPLING;     -   U.S. patent application Ser. No. 16/024,083, titled SAFETY         SYSTEMS FOR SMART POWERED SURGICAL STAPLING;     -   U.S. patent application Ser. No. 16/024,094, titled SURGICAL         SYSTEMS FOR DETECTING END EFFECTOR TISSUE DISTRIBUTION         IRREGULARITIES;     -   U.S. patent application Ser. No. 16/024,138, titled SYSTEMS FOR         DETECTING PROXIMITY OF SURGICAL END EFFECTOR TO CANCEROUS         TISSUE;     -   U.S. patent application Ser. No. 16/024,150, titled SURGICAL         INSTRUMENT CARTRIDGE SENSOR ASSEMBLIES;     -   U.S. patent application Ser. No. 16/024,160, titled VARIABLE         OUTPUT CARTRIDGE SENSOR ASSEMBLY;     -   U.S. patent application Ser. No. 16/024,124, titled SURGICAL         INSTRUMENT HAVING A FLEXIBLE ELECTRODE;     -   U.S. patent application Ser. No. 16/024,132, titled SURGICAL         INSTRUMENT HAVING A FLEXIBLE CIRCUIT;     -   U.S. patent application Ser. No. 16/024,141, titled SURGICAL         INSTRUMENT WITH A TISSUE MARKING ASSEMBLY;     -   U.S. patent application Ser. No. 16/024,162, titled SURGICAL         SYSTEMS WITH PRIORITIZED DATA TRANSMISSION CAPABILITIES;     -   U.S. patent application Ser. No. 16/024,066, titled SURGICAL         EVACUATION SENSING AND MOTOR CONTROL;     -   U.S. patent application Ser. No. 16/024,096, titled SURGICAL         EVACUATION SENSOR ARRANGEMENTS;     -   U.S. patent application Ser. No. 16/024,116, titled SURGICAL         EVACUATION FLOW PATHS;     -   U.S. patent application Ser. No. 16/024,149, titled SURGICAL         EVACUATION SENSING AND GENERATOR CONTROL;     -   U.S. patent application Ser. No. 16/024,180, titled SURGICAL         EVACUATION SENSING AND DISPLAY;     -   U.S. patent application Ser. No. 16/024,245, titled         COMMUNICATION OF SMOKE EVACUATION SYSTEM PARAMETERS TO HUB OR         CLOUD IN SMOKE EVACUATION MODULE FOR INTERACTIVE SURGICAL         PLATFORM;     -   U.S. patent application Ser. No. 16/024,258, titled SMOKE         EVACUATION SYSTEM INCLUDING A SEGMENTED CONTROL CIRCUIT FOR         INTERACTIVE SURGICAL PLATFORM;     -   U.S. patent application Ser. No. 16/024,265, titled SURGICAL         EVACUATION SYSTEM WITH A COMMUNICATION CIRCUIT FOR COMMUNICATION         BETWEEN A FILTER AND A SMOKE EVACUATION DEVICE; and     -   U.S. patent application Ser. No. 16/024,273, titled DUAL         IN-SERIES LARGE AND SMALL DROPLET FILTERS.

Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Jun. 28, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application Ser. No. 62/691,228, titled         A METHOD OF USING REINFORCED FLEX CIRCUITS WITH MULTIPLE SENSORS         WITH ELECTROSURGICAL DEVICES;     -   U.S. Provisional Patent Application Ser. No. 62/691,227, titled         CONTROLLING A SURGICAL INSTRUMENT ACCORDING TO SENSED CLOSURE         PARAMETERS;     -   U.S. Provisional Patent Application Ser. No. 62/691,230, titled         SURGICAL INSTRUMENT HAVING A FLEXIBLE ELECTRODE;     -   U.S. Provisional Patent Application Ser. No. 62/691,219, titled         SURGICAL EVACUATION SENSING AND MOTOR CONTROL;     -   U.S. Provisional Patent Application Ser. No. 62/691,257, titled         COMMUNICATION OF SMOKE EVACUATION SYSTEM PARAMETERS TO HUB OR         CLOUD IN SMOKE EVACUATION MODULE FOR INTERACTIVE SURGICAL         PLATFORM;     -   U.S. Provisional Patent Application Ser. No. 62/691,262, titled         SURGICAL EVACUATION SYSTEM WITH A COMMUNICATION CIRCUIT FOR         COMMUNICATION BETWEEN A FILTER AND A SMOKE EVACUATION DEVICE;         and     -   U.S. Provisional Patent Application Ser. No. 62/691,251, titled         DUAL IN-SERIES LARGE AND SMALL DROPLET FILTERS.

Applicant of the present application owns the following U.S. Provisional Patent Application, filed on Apr. 19, 2018, the disclosure of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application Ser. No. 62/659,900, titled         METHOD OF HUB COMMUNICATION.

Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Mar. 30, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application No. 62/650,898 filed on Mar.         30, 2018, titled CAPACITIVE COUPLED RETURN PATH PAD WITH         SEPARABLE ARRAY ELEMENTS;     -   U.S. Provisional Patent Application Ser. No. 62/650,887, titled         SURGICAL SYSTEMS WITH OPTIMIZED SENSING CAPABILITIES;     -   U.S. Provisional Patent Application Ser. No. 62/650,882, titled         SMOKE EVACUATION MODULE FOR INTERACTIVE SURGICAL PLATFORM; and     -   U.S. Provisional Patent Application Ser. No. 62/650,877, titled         SURGICAL SMOKE EVACUATION SENSING AND CONTROLS.

Applicant of the present application owns the following U.S. Patent Applications, filed on Mar. 29, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. patent application Ser. No. 15/940,641, titled INTERACTIVE         SURGICAL SYSTEMS WITH ENCRYPTED COMMUNICATION CAPABILITIES;     -   U.S. patent application Ser. No. 15/940,648, titled INTERACTIVE         SURGICAL SYSTEMS WITH CONDITION HANDLING OF DEVICES AND DATA         CAPABILITIES;     -   U.S. patent application Ser. No. 15/940,656, titled SURGICAL HUB         COORDINATION OF CONTROL AND COMMUNICATION OF OPERATING ROOM         DEVICES;     -   U.S. patent application Ser. No. 15/940,666, titled SPATIAL         AWARENESS OF SURGICAL HUBS IN OPERATING ROOMS;     -   U.S. patent application Ser. No. 15/940,670, titled COOPERATIVE         UTILIZATION OF DATA DERIVED FROM SECONDARY SOURCES BY         INTELLIGENT SURGICAL HUBS;     -   U.S. patent application Ser. No. 15/940,677, titled SURGICAL HUB         CONTROL ARRANGEMENTS;     -   U.S. patent application Ser. No. 15/940,632, titled DATA         STRIPPING METHOD TO INTERROGATE PATIENT RECORDS AND CREATE         ANONYMIZED RECORD;     -   U.S. patent application Ser. No. 15/940,640, titled         COMMUNICATION HUB AND STORAGE DEVICE FOR STORING PARAMETERS AND         STATUS OF A SURGICAL DEVICE TO BE SHARED WITH CLOUD BASED         ANALYTICS SYSTEMS;     -   U.S. patent application Ser. No. 15/940,645, titled SELF         DESCRIBING DATA PACKETS GENERATED AT AN ISSUING INSTRUMENT;     -   U.S. patent application Ser. No. 15/940,649, titled DATA PAIRING         TO INTERCONNECT A DEVICE MEASURED PARAMETER WITH AN OUTCOME;     -   U.S. patent application Ser. No. 15/940,654, titled SURGICAL HUB         SITUATIONAL AWARENESS;     -   U.S. patent application Ser. No. 15/940,663, titled SURGICAL         SYSTEM DISTRIBUTED PROCESSING;     -   U.S. patent application Ser. No. 15/940,668, titled AGGREGATION         AND REPORTING OF SURGICAL HUB DATA;     -   U.S. patent application Ser. No. 15/940,671, titled SURGICAL HUB         SPATIAL AWARENESS TO DETERMINE DEVICES IN OPERATING THEATER;     -   U.S. patent application Ser. No. 15/940,686, titled DISPLAY OF         ALIGNMENT OF STAPLE CARTRIDGE TO PRIOR LINEAR STAPLE LINE;     -   U.S. patent application Ser. No. 15/940,700, titled STERILE         FIELD INTERACTIVE CONTROL DISPLAYS;     -   U.S. patent application Ser. No. 15/940,629, titled COMPUTER         IMPLEMENTED INTERACTIVE SURGICAL SYSTEMS;     -   U.S. patent application Ser. No. 15/940,704, titled USE OF LASER         LIGHT AND RED-GREEN-BLUE COLORATION TO DETERMINE PROPERTIES OF         BACK SCATTERED LIGHT;     -   U.S. patent application Ser. No. 15/940,722, titled         CHARACTERIZATION OF TISSUE IRREGULARITIES THROUGH THE USE OF         MONO-CHROMATIC LIGHT REFRACTIVITY;     -   U.S. patent application Ser. No. 15/940,742, titled DUAL CMOS         ARRAY IMAGING;     -   U.S. patent application Ser. No. 15/940,636, titled ADAPTIVE         CONTROL PROGRAM UPDATES FOR SURGICAL DEVICES;     -   U.S. patent application Ser. No. 15/940,653, titled ADAPTIVE         CONTROL PROGRAM UPDATES FOR SURGICAL HUBS;     -   U.S. patent application Ser. No. 15/940,660, titled CLOUD-BASED         MEDICAL ANALYTICS FOR CUSTOMIZATION AND RECOMMENDATIONS TO A         USER;     -   U.S. patent application Ser. No. 15/940,679, titled CLOUD-BASED         MEDICAL ANALYTICS FOR LINKING OF LOCAL USAGE TRENDS WITH THE         RESOURCE ACQUISITION BEHAVIORS OF LARGER DATA SET;     -   U.S. patent application Ser. No. 15/940,694, titled CLOUD-BASED         MEDICAL ANALYTICS FOR MEDICAL FACILITY SEGMENTED         INDIVIDUALIZATION OF INSTRUMENT FUNCTION;     -   U.S. patent application Ser. No. 15/940,634, titled CLOUD-BASED         MEDICAL ANALYTICS FOR SECURITY AND AUTHENTICATION TRENDS AND         REACTIVE MEASURES;     -   U.S. patent application Ser. No. 15/940,706, titled DATA         HANDLING AND PRIORITIZATION IN A CLOUD ANALYTICS NETWORK;     -   U.S. patent application Ser. No. 15/940,675, titled CLOUD         INTERFACE FOR COUPLED SURGICAL DEVICES;     -   U.S. patent application Ser. No. 15/940,627, titled DRIVE         ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS;     -   U.S. patent application Ser. No. 15/940,637, titled         COMMUNICATION ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL         PLATFORMS;     -   U.S. patent application Ser. No. 15/940,642, titled CONTROLS FOR         ROBOT-ASSISTED SURGICAL PLATFORMS;     -   U.S. patent application Ser. No. 15/940,676, titled AUTOMATIC         TOOL ADJUSTMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS;     -   U.S. patent application Ser. No. 15/940,680, titled CONTROLLERS         FOR ROBOT-ASSISTED SURGICAL PLATFORMS;     -   U.S. patent application Ser. No. 15/940,683, titled COOPERATIVE         SURGICAL ACTIONS FOR ROBOT-ASSISTED SURGICAL PLATFORMS;     -   U.S. patent application Ser. No. 15/940,690, titled DISPLAY         ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS; and     -   U.S. patent application Ser. No. 15/940,711, titled SENSING         ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS.

Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Mar. 28, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application Ser. No. 62/649,302, titled         INTERACTIVE SURGICAL SYSTEMS WITH ENCRYPTED COMMUNICATION         CAPABILITIES;     -   U.S. Provisional Patent Application Ser. No. 62/649,294, titled         DATA STRIPPING METHOD TO INTERROGATE PATIENT RECORDS AND CREATE         ANONYMIZED RECORD;     -   U.S. Provisional Patent Application Ser. No. 62/649,300, titled         SURGICAL HUB SITUATIONAL AWARENESS;     -   U.S. Provisional Patent Application Ser. No. 62/649,309, titled         SURGICAL HUB SPATIAL AWARENESS TO DETERMINE DEVICES IN OPERATING         THEATER;     -   U.S. Provisional Patent Application Ser. No. 62/649,310, titled         COMPUTER IMPLEMENTED INTERACTIVE SURGICAL SYSTEMS;     -   U.S. Provisional Patent Application Ser. No. 62/649,291, titled         USE OF LASER LIGHT AND RED-GREEN-BLUE COLORATION TO DETERMINE         PROPERTIES OF BACK SCATTERED LIGHT;     -   U.S. Provisional Patent Application Ser. No. 62/649,296, titled         ADAPTIVE CONTROL PROGRAM UPDATES FOR SURGICAL DEVICES;     -   U.S. Provisional Patent Application Ser. No. 62/649,333, titled         CLOUD-BASED MEDICAL ANALYTICS FOR CUSTOMIZATION AND         RECOMMENDATIONS TO A USER;     -   U.S. Provisional Patent Application Ser. No. 62/649,327, titled         CLOUD-BASED MEDICAL ANALYTICS FOR SECURITY AND AUTHENTICATION         TRENDS AND REACTIVE MEASURES;     -   U.S. Provisional Patent Application Ser. No. 62/649,315, titled         DATA HANDLING AND PRIORITIZATION IN A CLOUD ANALYTICS NETWORK;     -   U.S. Provisional Patent Application Ser. No. 62/649,313, titled         CLOUD INTERFACE FOR COUPLED SURGICAL DEVICES;     -   U.S. Provisional Patent Application Ser. No. 62/649,320, titled         DRIVE ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS;     -   U.S. Provisional Patent Application Ser. No. 62/649,307, titled         AUTOMATIC TOOL ADJUSTMENTS FOR ROBOT-ASSISTED SURGICAL         PLATFORMS; and     -   U.S. Provisional Patent Application Ser. No. 62/649,323, titled         SENSING ARRANGEMENTS FOR ROBOT-ASSISTED SURGICAL PLATFORMS.

Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Mar. 8, 2018, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application Ser. No. 62/640,417, titled         TEMPERATURE CONTROL IN ULTRASONIC DEVICE AND CONTROL SYSTEM         THEREFOR; and     -   U.S. Provisional Patent Application Ser. No. 62/640,415, titled         ESTIMATING STATE OF ULTRASONIC END EFFECTOR AND CONTROL SYSTEM         THEREFOR.

Applicant of the present application owns the following U.S. Provisional Patent Applications, filed on Dec. 28, 2017, the disclosure of each of which is herein incorporated by reference in its entirety:

-   -   U.S. Provisional Patent Application Serial No. U.S. Provisional         Patent Application Ser. No. 62/611,341, titled INTERACTIVE         SURGICAL PLATFORM;     -   U.S. Provisional Patent Application Ser. No. 62/611,340, titled         CLOUD-BASED MEDICAL ANALYTICS; and     -   U.S. Provisional Patent Application Ser. No. 62/611,339, titled         ROBOT ASSISTED SURGICAL PLATFORM.

Before explaining various aspects of surgical devices and generators in detail, it should be noted that the illustrative examples are not limited in application or use to the details of construction and arrangement of parts illustrated in the accompanying drawings and description. The illustrative examples may be implemented or incorporated in other aspects, variations and modifications, and may be practiced or carried out in various ways. Further, unless otherwise indicated, the terms and expressions employed herein have been chosen for the purpose of describing the illustrative examples for the convenience of the reader and are not for the purpose of limitation thereof. Also, it will be appreciated that one or more of the following-described aspects, expressions of aspects, and/or examples, can be combined with any one or more of the other following-described aspects, expressions of aspects and/or examples.

Surgical Hubs

Referring to FIG. 1, a computer-implemented interactive surgical system 100 includes one or more surgical systems 102 and a cloud-based system (e.g., the cloud 104 that may include a remote server 113 coupled to a storage device 105). Each surgical system 102 includes at least one surgical hub 106 in communication with the cloud 104 that may include a remote server 113. In one example, as illustrated in FIG. 1, the surgical system 102 includes a visualization system 108, a robotic system 110, and a handheld intelligent surgical instrument 112, which are configured to communicate with one another and/or the hub 106. In some aspects, a surgical system 102 may include an M number of hubs 106, an N number of visualization systems 108, an O number of robotic systems 110, and a P number of handheld intelligent surgical instruments 112, where M, N, O, and P are integers greater than or equal to one.

In various aspects, the intelligent instruments 112 as described herein with reference to FIGS. 1-7 may be implemented as ultrasonic surgical instruments and combination energy surgical instruments 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F. The intelligent instruments 112 (e.g., devices 1 a-1 n) such as ultrasonic/combination surgical instruments 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F are configured to operate in a surgical data network 201 as described with reference to FIG. 8.

FIG. 2 depicts an example of a surgical system 102 being used to perform a surgical procedure on a patient who is lying down on an operating table 114 in a surgical operating room 116. A robotic system 110 is used in the surgical procedure as a part of the surgical system 102. The robotic system 110 includes a surgeon's console 118, a patient side cart 120 (surgical robot), and a surgical robotic hub 122. The patient side cart 120 can manipulate at least one removably coupled surgical tool 117 through a minimally invasive incision in the body of the patient while the surgeon views the surgical site through the surgeon's console 118. An image of the surgical site can be obtained by a medical imaging device 124, which can be manipulated by the patient side cart 120 to orient the imaging device 124. The robotic hub 122 can be used to process the images of the surgical site for subsequent display to the surgeon through the surgeon's console 118.

Other types of robotic systems can be readily adapted for use with the surgical system 102. Various examples of robotic systems and surgical tools that are suitable for use with the present disclosure are described in U.S. Provisional Patent Application Ser. No. 62/611,339, titled ROBOT ASSISTED SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety.

Various examples of cloud-based analytics that are performed by the cloud 104, and are suitable for use with the present disclosure, are described in U.S. Provisional Patent Application Ser. No. 62/611,340, titled CLOUD-BASED MEDICAL ANALYTICS, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety.

In various aspects, the imaging device 124 includes at least one image sensor and one or more optical components. Suitable image sensors include, but are not limited to, Charge-Coupled Device (CCD) sensors and Complementary Metal-Oxide Semiconductor (CMOS) sensors.

The optical components of the imaging device 124 may include one or more illumination sources and/or one or more lenses. The one or more illumination sources may be directed to illuminate portions of the surgical field. The one or more image sensors may receive light reflected or refracted from the surgical field, including light reflected or refracted from tissue and/or surgical instruments.

The one or more illumination sources may be configured to radiate electromagnetic energy in the visible spectrum as well as the invisible spectrum. The visible spectrum, sometimes referred to as the optical spectrum or luminous spectrum, is that portion of the electromagnetic spectrum that is visible to (i.e., can be detected by) the human eye and may be referred to as visible light or simply light. A typical human eye will respond to wavelengths in air that are from about 380 nm to about 750 nm.

The invisible spectrum (i.e., the non-luminous spectrum) is that portion of the electromagnetic spectrum that lies below and above the visible spectrum (i.e., wavelengths below about 380 nm and above about 750 nm). The invisible spectrum is not detectable by the human eye. Wavelengths greater than about 750 nm are longer than the red visible spectrum, and they become invisible infrared (IR), microwave, and radio electromagnetic radiation. Wavelengths less than about 380 nm are shorter than the violet spectrum, and they become invisible ultraviolet, x-ray, and gamma ray electromagnetic radiation.

In various aspects, the imaging device 124 is configured for use in a minimally invasive procedure. Examples of imaging devices suitable for use with the present disclosure include, but not limited to, an arthroscope, angioscope, bronchoscope, choledochoscope, colonoscope, cytoscope, duodenoscope, enteroscope, esophagogastro-duodenoscope (gastroscope), endoscope, laryngoscope, nasopharyngo-neproscope, sigmoidoscope, thoracoscope, and ureteroscope.

In one aspect, the imaging device employs multi-spectrum monitoring to discriminate topography and underlying structures. A multi-spectral image is one that captures image data within specific wavelength ranges across the electromagnetic spectrum. The wavelengths may be separated by filters or by the use of instruments that are sensitive to particular wavelengths, including light from frequencies beyond the visible light range, e.g., IR and ultraviolet. Spectral imaging can allow extraction of additional information the human eye fails to capture with its receptors for red, green, and blue. The use of multi-spectral imaging is described in greater detail under the heading “Advanced Imaging Acquisition Module” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. Multi-spectrum monitoring can be a useful tool in relocating a surgical field after a surgical task is completed to perform one or more of the previously described tests on the treated tissue.

It is axiomatic that strict sterilization of the operating room and surgical equipment is required during any surgery. The strict hygiene and sterilization conditions required in a “surgical theater,” i.e., an operating or treatment room, necessitate the highest possible sterility of all medical devices and equipment. Part of that sterilization process is the need to sterilize anything that comes in contact with the patient or penetrates the sterile field, including the imaging device 124 and its attachments and components. It will be appreciated that the sterile field may be considered a specified area, such as within a tray or on a sterile towel, that is considered free of microorganisms, or the sterile field may be considered an area, immediately around a patient, who has been prepared for a surgical procedure. The sterile field may include the scrubbed team members, who are properly attired, and all furniture and fixtures in the area.

In various aspects, the visualization system 108 includes one or more imaging sensors, one or more image-processing units, one or more storage arrays, and one or more displays that are strategically arranged with respect to the sterile field, as illustrated in FIG. 2. In one aspect, the visualization system 108 includes an interface for HL7, PACS, and EMR. Various components of the visualization system 108 are described under the heading “Advanced Imaging Acquisition Module” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety.

As illustrated in FIG. 2, a primary display 119 is positioned in the sterile field to be visible to an operator at the operating table 114. In addition, a visualization tower 111 is positioned outside the sterile field. The visualization tower 111 includes a first non-sterile display 107 and a second non-sterile display 109, which face away from each other. The visualization system 108, guided by the hub 106, is configured to utilize the displays 107, 109, and 119 to coordinate information flow to operators inside and outside the sterile field. For example, the hub 106 may cause the visualization system 108 to display a snapshot of a surgical site, as recorded by an imaging device 124, on a non-sterile display 107 or 109, while maintaining a live feed of the surgical site on the primary display 119. The snapshot on the non-sterile display 107 or 109 can permit a non-sterile operator to perform a diagnostic step relevant to the surgical procedure, for example.

In one aspect, the hub 106 is also configured to route a diagnostic input or feedback entered by a non-sterile operator at the visualization tower 111 to the primary display 119 within the sterile field, where it can be viewed by a sterile operator at the operating table. In one example, the input can be in the form of a modification to the snapshot displayed on the non-sterile display 107 or 109, which can be routed to the primary display 119 by the hub 106.

Referring to FIG. 2, a surgical instrument 112 is being used in the surgical procedure as part of the surgical system 102. The hub 106 is also configured to coordinate information flow to a display of the surgical instrument 112. For example, coordinate information flow is further described in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety. A diagnostic input or feedback entered by a non-sterile operator at the visualization tower 111 can be routed by the hub 106 to the surgical instrument display 115 within the sterile field, where it can be viewed by the operator of the surgical instrument 112. Example surgical instruments that are suitable for use with the surgical system 102 are described under the heading “Surgical Instrument Hardware” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, the disclosure of which is herein incorporated by reference in its entirety, for example.

Referring now to FIG. 3, a hub 106 is depicted in communication with a visualization system 108, a robotic system 110, and a handheld intelligent surgical instrument 112. The hub 106 includes a hub display 135, an imaging module 138, a generator module 140 (which can include a monopolar generator 142, a bipolar generator 144, and/or an ultrasonic generator 143), a communication module 130, a processor module 132, and a storage array 134. In certain aspects, as illustrated in FIG. 3, the hub 106 further includes a smoke evacuation module 126, a suction/irrigation module 128, and/or an OR mapping module 133.

During a surgical procedure, energy application to tissue, for sealing and/or cutting, is generally associated with smoke evacuation, suction of excess fluid, and/or irrigation of the tissue. Fluid, power, and/or data lines from different sources are often entangled during the surgical procedure. Valuable time can be lost addressing this issue during a surgical procedure. Detangling the lines may necessitate disconnecting the lines from their respective modules, which may require resetting the modules. The hub modular enclosure 136 offers a unified environment for managing the power, data, and fluid lines, which reduces the frequency of entanglement between such lines.

Aspects of the present disclosure present a surgical hub for use in a surgical procedure that involves energy application to tissue at a surgical site. The surgical hub includes a hub enclosure and a combo generator module slidably receivable in a docking station of the hub enclosure. The docking station includes data and power contacts. The combo generator module includes two or more of an ultrasonic energy generator component, a bipolar RF energy generator component, and a monopolar RF energy generator component that are housed in a single unit. In one aspect, the combo generator module also includes a smoke evacuation component, at least one energy delivery cable for connecting the combo generator module to a surgical instrument, at least one smoke evacuation component configured to evacuate smoke, fluid, and/or particulates generated by the application of therapeutic energy to the tissue, and a fluid line extending from the remote surgical site to the smoke evacuation component.

In one aspect, the fluid line is a first fluid line and a second fluid line extends from the remote surgical site to a suction and irrigation module slidably received in the hub enclosure. In one aspect, the hub enclosure comprises a fluid interface.

Certain surgical procedures may require the application of more than one energy type to the tissue. One energy type may be more beneficial for cutting the tissue, while another different energy type may be more beneficial for sealing the tissue. For example, a bipolar generator can be used to seal the tissue while an ultrasonic generator can be used to cut the sealed tissue. Aspects of the present disclosure present a solution where a hub modular enclosure 136 is configured to accommodate different generators, and facilitate an interactive communication therebetween. One of the advantages of the hub modular enclosure 136 is enabling the quick removal and/or replacement of various modules.

Aspects of the present disclosure present a modular surgical enclosure for use in a surgical procedure that involves energy application to tissue. The modular surgical enclosure includes a first energy-generator module, configured to generate a first energy for application to the tissue, and a first docking station comprising a first docking port that includes first data and power contacts, wherein the first energy-generator module is slidably movable into an electrical engagement with the power and data contacts and wherein the first energy-generator module is slidably movable out of the electrical engagement with the first power and data contacts,

Further to the above, the modular surgical enclosure also includes a second energy-generator module configured to generate a second energy, different than the first energy, for application to the tissue, and a second docking station comprising a second docking port that includes second data and power contacts, wherein the second energy-generator module is slidably movable into an electrical engagement with the power and data contacts, and wherein the second energy-generator module is slidably movable out of the electrical engagement with the second power and data contacts.

In addition, the modular surgical enclosure also includes a communication bus between the first docking port and the second docking port, configured to facilitate communication between the first energy-generator module and the second energy-generator module.

Referring to FIGS. 3-7, aspects of the present disclosure are presented for a hub modular enclosure 136 that allows the modular integration of a generator module 140, a smoke evacuation module 126, and a suction/irrigation module 128. The hub modular enclosure 136 further facilitates interactive communication between the modules 140, 126, 128. As illustrated in FIG. 5, the generator module 140 can be a generator module with integrated monopolar, bipolar, and ultrasonic components supported in a single housing unit 139 slidably insertable into the hub modular enclosure 136. As illustrated in FIG. 5, the generator module 140 can be configured to connect to a monopolar device 146, a bipolar device 147, and an ultrasonic device 148. Alternatively, the generator module 140 may comprise a series of monopolar, bipolar, and/or ultrasonic generator modules that interact through the hub modular enclosure 136. The hub modular enclosure 136 can be configured to facilitate the insertion of multiple generators and interactive communication between the generators docked into the hub modular enclosure 136 so that the generators would act as a single generator.

In one aspect, the hub modular enclosure 136 comprises a modular power and communication backplane 149 with external and wireless communication headers to enable the removable attachment of the modules 140, 126, 128 and interactive communication therebetween.

In one aspect, the hub modular enclosure 136 includes docking stations, or drawers, 151, herein also referred to as drawers, which are configured to slidably receive the modules 140, 126, 128. FIG. 4 illustrates a partial perspective view of a surgical hub enclosure 136, and a combo generator module 145 slidably receivable in a docking station 151 of the surgical hub enclosure 136. A docking port 152 with power and data contacts on a rear side of the combo generator module 145 is configured to engage a corresponding docking port 150 with power and data contacts of a corresponding docking station 151 of the hub modular enclosure 136 as the combo generator module 145 is slid into position within the corresponding docking station 151 of the hub module enclosure 136. In one aspect, the combo generator module 145 includes a bipolar, ultrasonic, and monopolar module and a smoke evacuation module integrated together into a single housing unit 139, as illustrated in FIG. 5.

In various aspects, the smoke evacuation module 126 includes a fluid line 154 that conveys captured/collected smoke and/or fluid away from a surgical site and to, for example, the smoke evacuation module 126. Vacuum suction originating from the smoke evacuation module 126 can draw the smoke into an opening of a utility conduit at the surgical site. The utility conduit, coupled to the fluid line, can be in the form of a flexible tube terminating at the smoke evacuation module 126. The utility conduit and the fluid line define a fluid path extending toward the smoke evacuation module 126 that is received in the hub enclosure 136.

In various aspects, the suction/irrigation module 128 is coupled to a surgical tool comprising an aspiration fluid line and a suction fluid line. In one example, the aspiration and suction fluid lines are in the form of flexible tubes extending from the surgical site toward the suction/irrigation module 128. One or more drive systems can be configured to cause irrigation and aspiration of fluids to and from the surgical site.

In one aspect, the surgical tool includes a shaft having an end effector at a distal end thereof and at least one energy treatment associated with the end effector, an aspiration tube, and an irrigation tube. The aspiration tube can have an inlet port at a distal end thereof and the aspiration tube extends through the shaft. Similarly, an irrigation tube can extend through the shaft and can have an inlet port in proximity to the energy deliver implement. The energy deliver implement is configured to deliver ultrasonic and/or RF energy to the surgical site and is coupled to the generator module 140 by a cable extending initially through the shaft.

The irrigation tube can be in fluid communication with a fluid source, and the aspiration tube can be in fluid communication with a vacuum source. The fluid source and/or the vacuum source can be housed in the suction/irrigation module 128. In one example, the fluid source and/or the vacuum source can be housed in the hub enclosure 136 separately from the suction/irrigation module 128. In such example, a fluid interface can be configured to connect the suction/irrigation module 128 to the fluid source and/or the vacuum source.

In one aspect, the modules 140, 126, 128 and/or their corresponding docking stations on the hub modular enclosure 136 may include alignment features that are configured to align the docking ports of the modules into engagement with their counterparts in the docking stations of the hub modular enclosure 136. For example, as illustrated in FIG. 4, the combo generator module 145 includes side brackets 155 that are configured to slidably engage with corresponding brackets 156 of the corresponding docking station 151 of the hub modular enclosure 136. The brackets cooperate to guide the docking port contacts of the combo generator module 145 into an electrical engagement with the docking port contacts of the hub modular enclosure 136.

In some aspects, the drawers 151 of the hub modular enclosure 136 are the same, or substantially the same size, and the modules are adjusted in size to be received in the drawers 151. For example, the side brackets 155 and/or 156 can be larger or smaller depending on the size of the module. In other aspects, the drawers 151 are different in size and are each designed to accommodate a particular module.

Furthermore, the contacts of a particular module can be keyed for engagement with the contacts of a particular drawer to avoid inserting a module into a drawer with mismatching contacts.

As illustrated in FIG. 4, the docking port 150 of one drawer 151 can be coupled to the docking port 150 of another drawer 151 through a communications link 157 to facilitate an interactive communication between the modules housed in the hub modular enclosure 136. The docking ports 150 of the hub modular enclosure 136 may alternatively, or additionally, facilitate a wireless interactive communication between the modules housed in the hub modular enclosure 136. Any suitable wireless communication can be employed, such as for example Air Titan-Bluetooth.

FIG. 6 illustrates individual power bus attachments for a plurality of lateral docking ports of a lateral modular housing 160 configured to receive a plurality of modules of a surgical hub 206. The lateral modular housing 160 is configured to laterally receive and interconnect the modules 161. The modules 161 are slidably inserted into docking stations 162 of lateral modular housing 160, which includes a backplane for interconnecting the modules 161. As illustrated in FIG. 6, the modules 161 are arranged laterally in the lateral modular housing 160. Alternatively, the modules 161 may be arranged vertically in a lateral modular housing.

FIG. 7 illustrates a vertical modular housing 164 configured to receive a plurality of modules 165 of the surgical hub 106. The modules 165 are slidably inserted into docking stations, or drawers, 167 of vertical modular housing 164, which includes a backplane for interconnecting the modules 165. Although the drawers 167 of the vertical modular housing 164 are arranged vertically, in certain instances, a vertical modular housing 164 may include drawers that are arranged laterally. Furthermore, the modules 165 may interact with one another through the docking ports of the vertical modular housing 164. In the example of FIG. 7, a display 177 is provided for displaying data relevant to the operation of the modules 165. In addition, the vertical modular housing 164 includes a master module 178 housing a plurality of sub-modules that are slidably received in the master module 178.

In various aspects, the imaging module 138 comprises an integrated video processor and a modular light source and is adapted for use with various imaging devices. In one aspect, the imaging device is comprised of a modular housing that can be assembled with a light source module and a camera module. The housing can be a disposable housing. In at least one example, the disposable housing is removably coupled to a reusable controller, a light source module, and a camera module. The light source module and/or the camera module can be selectively chosen depending on the type of surgical procedure. In one aspect, the camera module comprises a CCD sensor. In another aspect, the camera module comprises a CMOS sensor. In another aspect, the camera module is configured for scanned beam imaging. Likewise, the light source module can be configured to deliver a white light or a different light, depending on the surgical procedure.

During a surgical procedure, removing a surgical device from the surgical field and replacing it with another surgical device that includes a different camera or a different light source can be inefficient. Temporarily losing sight of the surgical field may lead to undesirable consequences. The module imaging device of the present disclosure is configured to permit the replacement of a light source module or a camera module midstream during a surgical procedure, without having to remove the imaging device from the surgical field.

In one aspect, the imaging device comprises a tubular housing that includes a plurality of channels. A first channel is configured to slidably receive the camera module, which can be configured for a snap-fit engagement with the first channel. A second channel is configured to slidably receive the light source module, which can be configured for a snap-fit engagement with the second channel. In another example, the camera module and/or the light source module can be rotated into a final position within their respective channels. A threaded engagement can be employed in lieu of the snap-fit engagement.

In various examples, multiple imaging devices are placed at different positions in the surgical field to provide multiple views. The imaging module 138 can be configured to switch between the imaging devices to provide an optimal view. In various aspects, the imaging module 138 can be configured to integrate the images from the different imaging device.

Various image processors and imaging devices suitable for use with the present disclosure are described in U.S. Pat. No. 7,995,045, titled COMBINED SBI AND CONVENTIONAL IMAGE PROCESSOR, which issued on Aug. 9, 2011, which is herein incorporated by reference in its entirety. In addition, U.S. Pat. No. 7,982,776, titled SBI MOTION ARTIFACT REMOVAL APPARATUS AND METHOD, which issued on Jul. 19, 2011, which is herein incorporated by reference in its entirety, describes various systems for removing motion artifacts from image data. Such systems can be integrated with the imaging module 138. Furthermore, U.S. Patent Application Publication No. 2011/0306840, titled CONTROLLABLE MAGNETIC SOURCE TO FIXTURE INTRACORPOREAL APPARATUS, which published on Dec. 15, 2011, and U.S. Patent Application Publication No. 2014/0243597, titled SYSTEM FOR PERFORMING A MINIMALLY INVASIVE SURGICAL PROCEDURE, which published on Aug. 28, 2014, each of which is herein incorporated by reference in its entirety.

FIG. 8 illustrates a surgical data network 201 comprising a modular communication hub 203 configured to connect modular devices located in one or more operating theaters of a healthcare facility, or any room in a healthcare facility specially equipped for surgical operations, to a cloud-based system (e.g., the cloud 204 that may include a remote server 213 coupled to a storage device 205). In one aspect, the modular communication hub 203 comprises a network hub 207 and/or a network switch 209 in communication with a network router. The modular communication hub 203 also can be coupled to a local computer system 210 to provide local computer processing and data manipulation. The surgical data network 201 may be configured as passive, intelligent, or switching. A passive surgical data network serves as a conduit for the data, enabling it to go from one device (or segment) to another and to the cloud computing resources. An intelligent surgical data network includes additional features to enable the traffic passing through the surgical data network to be monitored and to configure each port in the network hub 207 or network switch 209. An intelligent surgical data network may be referred to as a manageable hub or switch. A switching hub reads the destination address of each packet and then forwards the packet to the correct port.

Modular devices 1 a-1 n located in the operating theater may be coupled to the modular communication hub 203. The network hub 207 and/or the network switch 209 may be coupled to a network router 211 to connect the devices 1 a-1 n to the cloud 204 or the local computer system 210. Data associated with the devices 1 a-1 n may be transferred to cloud-based computers via the router for remote data processing and manipulation. Data associated with the devices 1 a-1 n may also be transferred to the local computer system 210 for local data processing and manipulation. Modular devices 2 a-2 m located in the same operating theater also may be coupled to a network switch 209. The network switch 209 may be coupled to the network hub 207 and/or the network router 211 to connect to the devices 2 a-2 m to the cloud 204. Data associated with the devices 2 a-2 n may be transferred to the cloud 204 via the network router 211 for data processing and manipulation. Data associated with the devices 2 a-2 m may also be transferred to the local computer system 210 for local data processing and manipulation.

It will be appreciated that the surgical data network 201 may be expanded by interconnecting multiple network hubs 207 and/or multiple network switches 209 with multiple network routers 211. The modular communication hub 203 may be contained in a modular control tower configured to receive multiple devices 1 a-1 n/2 a-2 m. The local computer system 210 also may be contained in a modular control tower. The modular communication hub 203 is connected to a display 212 to display images obtained by some of the devices 1 a-1 n/2 a-2 m, for example during surgical procedures. In various aspects, the devices 1 a-1 n/2 a-2 m may include, for example, various modules such as an imaging module 138 coupled to an endoscope, a generator module 140 coupled to an energy-based surgical device, a smoke evacuation module 126, a suction/irrigation module 128, a communication module 130, a processor module 132, a storage array 134, a surgical device coupled to a display, and/or a non-contact sensor module, among other modular devices that may be connected to the modular communication hub 203 of the surgical data network 201.

In one aspect, the surgical data network 201 may comprise a combination of network hub(s), network switch(es), and network router(s) connecting the devices 1 a-1 n/2 a-2 m to the cloud. Any one of or all of the devices 1 a-1 n/2 a-2 m coupled to the network hub or network switch may collect data in real time and transfer the data to cloud computers for data processing and manipulation. It will be appreciated that cloud computing relies on sharing computing resources rather than having local servers or personal devices to handle software applications. The word “cloud” may be used as a metaphor for “the Internet,” although the term is not limited as such. Accordingly, the term “cloud computing” may be used herein to refer to “a type of Internet-based computing,” where different services—such as servers, storage, and applications—are delivered to the modular communication hub 203 and/or computer system 210 located in the surgical theater (e.g., a fixed, mobile, temporary, or field operating room or space) and to devices connected to the modular communication hub 203 and/or computer system 210 through the Internet. The cloud infrastructure may be maintained by a cloud service provider. In this context, the cloud service provider may be the entity that coordinates the usage and control of the devices 1 a-1 n/2 a-2 m located in one or more operating theaters. The cloud computing services can perform a large number of calculations based on the data gathered by smart surgical instruments, robots, and other computerized devices located in the operating theater. The hub hardware enables multiple devices or connections to be connected to a computer that communicates with the cloud computing resources and storage.

Applying cloud computer data processing techniques on the data collected by the devices 1 a-1 n/2 a-2 m, the surgical data network provides improved surgical outcomes, reduced costs, and improved patient satisfaction. At least some of the devices 1 a-1 n/2 a-2 m may be employed to view tissue states to assess leaks or perfusion of sealed tissue after a tissue sealing and cutting procedure. At least some of the devices 1 a-1 n/2 a-2 m may be employed to identify pathology, such as the effects of diseases, using the cloud-based computing to examine data including images of samples of body tissue for diagnostic purposes. This includes localization and margin confirmation of tissue and phenotypes. At least some of the devices 1 a-1 n/2 a-2 m may be employed to identify anatomical structures of the body using a variety of sensors integrated with imaging devices and techniques such as overlaying images captured by multiple imaging devices. The data gathered by the devices 1 a-1 n/2 a-2 m, including image data, may be transferred to the cloud 204 or the local computer system 210 or both for data processing and manipulation including image processing and manipulation. The data may be analyzed to improve surgical procedure outcomes by determining if further treatment, such as the application of endoscopic intervention, emerging technologies, a targeted radiation, targeted intervention, and precise robotics to tissue-specific sites and conditions, may be pursued. Such data analysis may further employ outcome analytics processing, and using standardized approaches may provide beneficial feedback to either confirm surgical treatments and the behavior of the surgeon or suggest modifications to surgical treatments and the behavior of the surgeon.

In one implementation, the operating theater devices 1 a-1 n may be connected to the modular communication hub 203 over a wired channel or a wireless channel depending on the configuration of the devices 1 a-1 n to a network hub. The network hub 207 may be implemented, in one aspect, as a local network broadcast device that works on the physical layer of the Open System Interconnection (OSI) model. The network hub provides connectivity to the devices 1 a-1 n located in the same operating theater network. The network hub 207 collects data in the form of packets and sends them to the router in half duplex mode. The network hub 207 does not store any media access control/Internet Protocol (MAC/IP) to transfer the device data. Only one of the devices 1 a-1 n can send data at a time through the network hub 207. The network hub 207 has no routing tables or intelligence regarding where to send information and broadcasts all network data across each connection and to a remote server 213 (FIG. 9) over the cloud 204. The network hub 207 can detect basic network errors such as collisions, but having all information broadcast to multiple ports can be a security risk and cause bottlenecks.

In another implementation, the operating theater devices 2 a-2 m may be connected to a network switch 209 over a wired channel or a wireless channel. The network switch 209 works in the data link layer of the OSI model. The network switch 209 is a multicast device for connecting the devices 2 a-2 m located in the same operating theater to the network. The network switch 209 sends data in the form of frames to the network router 211 and works in full duplex mode. Multiple devices 2 a-2 m can send data at the same time through the network switch 209. The network switch 209 stores and uses MAC addresses of the devices 2 a-2 m to transfer data.

The network hub 207 and/or the network switch 209 are coupled to the network router 211 for connection to the cloud 204. The network router 211 works in the network layer of the OSI model. The network router 211 creates a route for transmitting data packets received from the network hub 207 and/or network switch 211 to cloud-based computer resources for further processing and manipulation of the data collected by any one of or all the devices 1 a-1 n/2 a-2 m. The network router 211 may be employed to connect two or more different networks located in different locations, such as, for example, different operating theaters of the same healthcare facility or different networks located in different operating theaters of different healthcare facilities. The network router 211 sends data in the form of packets to the cloud 204 and works in full duplex mode. Multiple devices can send data at the same time. The network router 211 uses IP addresses to transfer data.

In one example, the network hub 207 may be implemented as a USB hub, which allows multiple USB devices to be connected to a host computer. The USB hub may expand a single USB port into several tiers so that there are more ports available to connect devices to the host system computer. The network hub 207 may include wired or wireless capabilities to receive information over a wired channel or a wireless channel. In one aspect, a wireless USB short-range, high-bandwidth wireless radio communication protocol may be employed for communication between the devices 1 a-1 n and devices 2 a-2 m located in the operating theater.

In other examples, the operating theater devices 1 a-1 n/2 a-2 m may communicate to the modular communication hub 203 via Bluetooth wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz) from fixed and mobile devices and building personal area networks (PANs). In other aspects, the operating theater devices 1 a-1 n/2 a-2 m may communicate to the modular communication hub 203 via a number of wireless or wired communication standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long-term evolution (LTE), and Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, and Ethernet derivatives thereof, as well as any other wireless and wired protocols that are designated as 3G, 4G, 5G, and beyond. The computing module may include a plurality of communication modules. For instance, a first communication module may be dedicated to shorter-range wireless communications such as Wi-Fi and Bluetooth, and a second communication module may be dedicated to longer-range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.

The modular communication hub 203 may serve as a central connection for one or all of the operating theater devices 1 a-1 n/2 a-2 m and handles a data type known as frames. Frames carry the data generated by the devices 1 a-1 n/2 a-2 m. When a frame is received by the modular communication hub 203, it is amplified and transmitted to the network router 211, which transfers the data to the cloud computing resources by using a number of wireless or wired communication standards or protocols, as described herein.

The modular communication hub 203 can be used as a standalone device or be connected to compatible network hubs and network switches to form a larger network. The modular communication hub 203 is generally easy to install, configure, and maintain, making it a good option for networking the operating theater devices 1 a-1 n/2 a-2 m.

FIG. 9 illustrates a computer-implemented interactive surgical system 200. The computer-implemented interactive surgical system 200 is similar in many respects to the computer-implemented interactive surgical system 100. For example, the computer-implemented interactive surgical system 200 includes one or more surgical systems 202, which are similar in many respects to the surgical systems 102. Each surgical system 202 includes at least one surgical hub 206 in communication with a cloud 204 that may include a remote server 213. In one aspect, the computer-implemented interactive surgical system 200 comprises a modular control tower 236 connected to multiple operating theater devices such as, for example, intelligent surgical instruments, robots, and other computerized devices located in the operating theater. As shown in FIG. 10, the modular control tower 236 comprises a modular communication hub 203 coupled to a computer system 210. As illustrated in the example of FIG. 9, the modular control tower 236 is coupled to an imaging module 238 that is coupled to an endoscope 239, a generator module 240 that is coupled to an energy device 241, a smoke evacuator module 226, a suction/irrigation module 228, a communication module 230, a processor module 232, a storage array 234, a smart device/instrument 235 optionally coupled to a display 237, and a non-contact sensor module 242. The operating theater devices are coupled to cloud computing resources and data storage via the modular control tower 236. A robot hub 222 also may be connected to the modular control tower 236 and to the cloud computing resources. The devices/instruments 235, visualization systems 208, among others, may be coupled to the modular control tower 236 via wired or wireless communication standards or protocols, as described herein. The modular control tower 236 may be coupled to a hub display 215 (e.g., monitor, screen) to display and overlay images received from the imaging module, device/instrument display, and/or other visualization systems 208. The hub display also may display data received from devices connected to the modular control tower in conjunction with images and overlaid images.

FIG. 10 illustrates a surgical hub 206 comprising a plurality of modules coupled to the modular control tower 236. The modular control tower 236 comprises a modular communication hub 203, e.g., a network connectivity device, and a computer system 210 to provide local processing, visualization, and imaging, for example. As shown in FIG. 10, the modular communication hub 203 may be connected in a tiered configuration to expand the number of modules (e.g., devices) that may be connected to the modular communication hub 203 and transfer data associated with the modules to the computer system 210, cloud computing resources, or both. As shown in FIG. 10, each of the network hubs/switches in the modular communication hub 203 includes three downstream ports and one upstream port. The upstream network hub/switch is connected to a processor to provide a communication connection to the cloud computing resources and a local display 217. Communication to the cloud 204 may be made either through a wired or a wireless communication channel.

The surgical hub 206 employs a non-contact sensor module 242 to measure the dimensions of the operating theater and generate a map of the surgical theater using either ultrasonic or laser-type non-contact measurement devices. An ultrasound-based non-contact sensor module scans the operating theater by transmitting a burst of ultrasound and receiving the echo when it bounces off the perimeter walls of an operating theater as described under the heading “Surgical Hub Spatial Awareness Within an Operating Room” in U.S. Provisional Patent Application Ser. No. 62/611,341, titled INTERACTIVE SURGICAL PLATFORM, filed Dec. 28, 2017, which is herein incorporated by reference in its entirety, in which the sensor module is configured to determine the size of the operating theater and to adjust Bluetooth-pairing distance limits. A laser-based non-contact sensor module scans the operating theater by transmitting laser light pulses, receiving laser light pulses that bounce off the perimeter walls of the operating theater, and comparing the phase of the transmitted pulse to the received pulse to determine the size of the operating theater and to adjust Bluetooth pairing distance limits, for example.

The computer system 210 comprises a processor 244 and a network interface 245. The processor 244 is coupled to a communication module 247, storage 248, memory 249, non-volatile memory 250, and input/output interface 251 via a system bus. The system bus can be any of several types of bus structure(s) including the memory bus or memory controller, a peripheral bus or external bus, and/or a local bus using any variety of available bus architectures including, but not limited to, 9-bit bus, Industrial Standard Architecture (ISA), Micro-Charmel Architecture (MSA), Extended ISA (EISA), Intelligent Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), USB, Advanced Graphics Port (AGP), Personal Computer Memory Card International Association bus (PCMCIA), Small Computer Systems Interface (SCSI), or any other proprietary bus.

The processor 244 may be any single-core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one aspect, the processor may be an LM4F230H5QR ARM Cortex-M4F Processor Core, available from Texas Instruments, for example, comprising an on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), an internal read-only memory (ROM) loaded with StellarisWare® software, a 2 KB electrically erasable programmable read-only memory (EEPROM), and/or one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analogs, one or more 12-bit analog-to-digital converters (ADCs) with 12 analog input channels, details of which are available for the product datasheet.

In one aspect, the processor 244 may comprise a safety controller comprising two controller-based families such as TMS570 and RM4x, known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. The safety controller may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options.

The system memory includes volatile memory and non-volatile memory. The basic input/output system (BIOS), containing the basic routines to transfer information between elements within the computer system, such as during start-up, is stored in non-volatile memory. For example, the non-volatile memory can include ROM, programmable ROM (PROM), electrically programmable ROM (EPROM), EEPROM, or flash memory. Volatile memory includes random-access memory (RAM), which acts as external cache memory. Moreover, RAM is available in many forms such as SRAM, dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM).

The computer system 210 also includes removable/non-removable, volatile/non-volatile computer storage media, such as for example disk storage. The disk storage includes, but is not limited to, devices like a magnetic disk drive, floppy disk drive, tape drive, Jaz drive, Zip drive, LS-60 drive, flash memory card, or memory stick. In addition, the disk storage can include storage media separately or in combination with other storage media including, but not limited to, an optical disc drive such as a compact disc ROM device (CD-ROM), compact disc recordable drive (CD-R Drive), compact disc rewritable drive (CD-RW Drive), or a digital versatile disc ROM drive (DVD-ROM). To facilitate the connection of the disk storage devices to the system bus, a removable or non-removable interface may be employed.

It is to be appreciated that the computer system 210 includes software that acts as an intermediary between users and the basic computer resources described in a suitable operating environment. Such software includes an operating system. The operating system, which can be stored on the disk storage, acts to control and allocate resources of the computer system. System applications take advantage of the management of resources by the operating system through program modules and program data stored either in the system memory or on the disk storage. It is to be appreciated that various components described herein can be implemented with various operating systems or combinations of operating systems.

A user enters commands or information into the computer system 210 through input device(s) coupled to the I/O interface 251. The input devices include, but are not limited to, a pointing device such as a mouse, trackball, stylus, touch pad, keyboard, microphone, joystick, game pad, satellite dish, scanner, TV tuner card, digital camera, digital video camera, web camera, and the like. These and other input devices connect to the processor through the system bus via interface port(s). The interface port(s) include, for example, a serial port, a parallel port, a game port, and a USB. The output device(s) use some of the same types of ports as input device(s). Thus, for example, a USB port may be used to provide input to the computer system and to output information from the computer system to an output device. An output adapter is provided to illustrate that there are some output devices like monitors, displays, speakers, and printers, among other output devices that require special adapters. The output adapters include, by way of illustration and not limitation, video and sound cards that provide a means of connection between the output device and the system bus. It should be noted that other devices and/or systems of devices, such as remote computer(s), provide both input and output capabilities.

The computer system 210 can operate in a networked environment using logical connections to one or more remote computers, such as cloud computer(s), or local computers. The remote cloud computer(s) can be a personal computer, server, router, network PC, workstation, microprocessor-based appliance, peer device, or other common network node, and the like, and typically includes many or all of the elements described relative to the computer system. For purposes of brevity, only a memory storage device is illustrated with the remote computer(s). The remote computer(s) is logically connected to the computer system through a network interface and then physically connected via a communication connection. The network interface encompasses communication networks such as local area networks (LANs) and wide area networks (WANs). LAN technologies include Fiber Distributed Data Interface (FDDI), Copper Distributed Data Interface (CDDI), Ethernet/IEEE 802.3, Token Ring/IEEE 802.5 and the like. WAN technologies include, but are not limited to, point-to-point links, circuit-switching networks like Integrated Services Digital Networks (ISDN) and variations thereon, packet-switching networks, and Digital Subscriber Lines (DSL).

In various aspects, the computer system 210 of FIG. 10, the imaging module 238 and/or visualization system 208, and/or the processor module 232 of FIGS. 9-10, may comprise an image processor, image-processing engine, media processor, or any specialized digital signal processor (DSP) used for the processing of digital images. The image processor may employ parallel computing with single instruction, multiple data (SIMD) or multiple instruction, multiple data (MIMD) technologies to increase speed and efficiency. The digital image-processing engine can perform a range of tasks. The image processor may be a system on a chip with multicore processor architecture.

The communication connection(s) refers to the hardware/software employed to connect the network interface to the bus. While the communication connection is shown for illustrative clarity inside the computer system, it can also be external to the computer system 210. The hardware/software necessary for connection to the network interface includes, for illustrative purposes only, internal and external technologies such as modems, including regular telephone-grade modems, cable modems, and DSL modems, ISDN adapters, and Ethernet cards.

In various aspects, the devices/instruments 235 described with reference to FIGS. 9-10, may be implemented as ultrasonic surgical instruments and combination energy surgical instruments 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F.

Accordingly, the ultrasonic/combination surgical instrument 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F is configured to interface with the modular control tower 236 and the surgical hub 206. Once connected to the surgical hub 206, the ultrasonic/combination surgical instrument 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F is configured to interface with the cloud 204, the server 213, other hub connected instruments, the hub display 215, or the visualization system 209, or combinations thereof. Further, once connected to hub 206, the ultrasonic/combination surgical instrument 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F may utilize the processing circuits available in the hub local computer system 210.

FIG. 11 illustrates a functional block diagram of one aspect of a USB network hub 300 device, in accordance with at least one aspect of the present disclosure. In the illustrated aspect, the USB network hub device 300 employs a TUSB2036 integrated circuit hub by Texas Instruments. The USB network hub 300 is a CMOS device that provides an upstream USB transceiver port 302 and up to three downstream USB transceiver ports 304, 306, 308 in compliance with the USB 2.0 specification. The upstream USB transceiver port 302 is a differential root data port comprising a differential data minus (DM0) input paired with a differential data plus (DP0) input. The three downstream USB transceiver ports 304, 306, 308 are differential data ports where each port includes differential data plus (DP1-DP3) outputs paired with differential data minus (DM1-DM3) outputs.

The USB network hub 300 device is implemented with a digital state machine instead of a microcontroller, and no firmware programming is required. Fully compliant USB transceivers are integrated into the circuit for the upstream USB transceiver port 302 and all downstream USB transceiver ports 304, 306, 308. The downstream USB transceiver ports 304, 306, 308 support both full-speed and low-speed devices by automatically setting the slew rate according to the speed of the device attached to the ports. The USB network hub 300 device may be configured either in bus-powered or self-powered mode and includes a hub power logic 312 to manage power.

The USB network hub 300 device includes a serial interface engine 310 (SIE). The SIE 310 is the front end of the USB network hub 300 hardware and handles most of the protocol described in chapter 8 of the USB specification. The SIE 310 typically comprehends signaling up to the transaction level. The functions that it handles could include: packet recognition, transaction sequencing, SOP, EOP, RESET, and RESUME signal detection/generation, clock/data separation, non-return-to-zero invert (NRZI) data encoding/decoding and bit-stuffing, CRC generation and checking (token and data), packet ID (PID) generation and checking/decoding, and/or serial-parallel/parallel-serial conversion. The 310 receives a clock input 314 and is coupled to a suspend/resume logic and frame timer 316 circuit and a hub repeater circuit 318 to control communication between the upstream USB transceiver port 302 and the downstream USB transceiver ports 304, 306, 308 through port logic circuits 320, 322, 324. The SIE 310 is coupled to a command decoder 326 via interface logic 328 to control commands from a serial EEPROM via a serial EEPROM interface 330.

In various aspects, the USB network hub 300 can connect 127 functions configured in up to six logical layers (tiers) to a single computer. Further, the USB network hub 300 can connect to all peripherals using a standardized four-wire cable that provides both communication and power distribution. The power configurations are bus-powered and self-powered modes. The USB network hub 300 may be configured to support four modes of power management: a bus-powered hub, with either individual-port power management or ganged-port power management, and the self-powered hub, with either individual-port power management or ganged-port power management. In one aspect, using a USB cable, the USB network hub 300, the upstream USB transceiver port 302 is plugged into a USB host controller, and the downstream USB transceiver ports 304, 306, 308 are exposed for connecting USB compatible devices, and so forth.

Additional details regarding the structure and function of the surgical hub and/or surgical hub networks can be found in U.S. Provisional Patent Application No. 62/659,900, titled METHOD OF HUB COMMUNICATION, filed Apr. 19, 2018, which is hereby incorporated by reference herein in its entirety.

Cloud System Hardware and Functional Modules

FIG. 12 is a block diagram of the computer-implemented interactive surgical system, in accordance with at least one aspect of the present disclosure. In one aspect, the computer-implemented interactive surgical system is configured to monitor and analyze data related to the operation of various surgical systems that include surgical hubs, surgical instruments, robotic devices and operating theaters or healthcare facilities. The computer-implemented interactive surgical system comprises a cloud-based analytics system. Although the cloud-based analytics system is described as a surgical system, it is not necessarily limited as such and could be a cloud-based medical system generally. As illustrated in FIG. 12, the cloud-based analytics system comprises a plurality of surgical instruments 7012 (may be the same or similar to instruments 112), a plurality of surgical hubs 7006 (may be the same or similar to hubs 106), and a surgical data network 7001 (may be the same or similar to network 201) to couple the surgical hubs 7006 to the cloud 7004 (may be the same or similar to cloud 204). Each of the plurality of surgical hubs 7006 is communicatively coupled to one or more surgical instruments 7012. The hubs 7006 are also communicatively coupled to the cloud 7004 of the computer-implemented interactive surgical system via the network 7001. The cloud 7004 is a remote centralized source of hardware and software for storing, manipulating, and communicating data generated based on the operation of various surgical systems. As shown in FIG. 12, access to the cloud 7004 is achieved via the network 7001, which may be the Internet or some other suitable computer network. Surgical hubs 7006 that are coupled to the cloud 7004 can be considered the client side of the cloud computing system (i.e., cloud-based analytics system). Surgical instruments 7012 are paired with the surgical hubs 7006 for control and implementation of various surgical procedures or operations as described herein.

In addition, surgical instruments 7012 may comprise transceivers for data transmission to and from their corresponding surgical hubs 7006 (which may also comprise transceivers). Combinations of surgical instruments 7012 and corresponding hubs 7006 may indicate particular locations, such as operating theaters in healthcare facilities (e.g., hospitals), for providing medical operations. For example, the memory of a surgical hub 7006 may store location data. As shown in FIG. 12, the cloud 7004 comprises central servers 7013 (which may be same or similar to remote server 113 in FIG. 1 and/or remote server 213 in FIG. 9), hub application servers 7002, data analytics modules 7034, and an input/output (“I/O”) interface 7007. The central servers 7013 of the cloud 7004 collectively administer the cloud computing system, which includes monitoring requests by client surgical hubs 7006 and managing the processing capacity of the cloud 7004 for executing the requests. Each of the central servers 7013 comprises one or more processors 7008 coupled to suitable memory devices 7010 which can include volatile memory such as random-access memory (RAM) and non-volatile memory such as magnetic storage devices. The memory devices 7010 may comprise machine executable instructions that when executed cause the processors 7008 to execute the data analytics modules 7034 for the cloud-based data analysis, operations, recommendations and other operations described below. Moreover, the processors 7008 can execute the data analytics modules 7034 independently or in conjunction with hub applications independently executed by the hubs 7006. The central servers 7013 also comprise aggregated medical data databases 2212, which can reside in the memory 2210.

Based on connections to various surgical hubs 7006 via the network 7001, the cloud 7004 can aggregate data from specific data generated by various surgical instruments 7012 and their corresponding hubs 7006. Such aggregated data may be stored within the aggregated medical databases 7011 of the cloud 7004. In particular, the cloud 7004 may advantageously perform data analysis and operations on the aggregated data to yield insights and/or perform functions that individual hubs 7006 could not achieve on their own. To this end, as shown in FIG. 12, the cloud 7004 and the surgical hubs 7006 are communicatively coupled to transmit and receive information. The I/O interface 7007 is connected to the plurality of surgical hubs 7006 via the network 7001. In this way, the I/O interface 7007 can be configured to transfer information between the surgical hubs 7006 and the aggregated medical data databases 7011. Accordingly, the I/O interface 7007 may facilitate read/write operations of the cloud-based analytics system. Such read/write operations may be executed in response to requests from hubs 7006. These requests could be transmitted to the hubs 7006 through the hub applications. The I/O interface 7007 may include one or more high speed data ports, which may include universal serial bus (USB) ports, IEEE 1394 ports, as well as W-Fi and Bluetooth I/O interfaces for connecting the cloud 7004 to hubs 7006. The hub application servers 7002 of the cloud 7004 are configured to host and supply shared capabilities to software applications (e.g. hub applications) executed by surgical hubs 7006. For example, the hub application servers 7002 may manage requests made by the hub applications through the hubs 7006, control access to the aggregated medical data databases 7011, and perform load balancing. The data analytics modules 7034 are described in further detail with reference to FIG. 13.

The particular cloud computing system configuration described in the present disclosure is specifically designed to address various issues arising in the context of medical operations and procedures performed using medical devices, such as the surgical instruments 7012, 112. In particular, the surgical instruments 7012 may be digital surgical devices configured to interact with the cloud 7004 for implementing techniques to improve the performance of surgical operations. Various surgical instruments 7012 and/or surgical hubs 7006 may comprise touch controlled user interfaces such that clinicians may control aspects of interaction between the surgical instruments 7012 and the cloud 7004. Other suitable user interfaces for control such as auditory controlled user interfaces can also be used.

FIG. 13 is a block diagram which illustrates the functional architecture of the computer-implemented interactive surgical system, in accordance with at least one aspect of the present disclosure. The cloud-based analytics system includes a plurality of data analytics modules 7034 that may be executed by the processors 7008 of the cloud 7004 for providing data analytic solutions to problems specifically arising in the medical field. As shown in FIG. 13, the functions of the cloud-based data analytics modules 7034 may be assisted via hub applications 7014 hosted by the hub application servers 7002 that may be accessed on surgical hubs 7006. The cloud processors 7008 and hub applications 7014 may operate in conjunction to execute the data analytics modules 7034. Application program interfaces (APIs) 7016 define the set of protocols and routines corresponding to the hub applications 7014. Additionally, the APIs 7016 manage the storing and retrieval of data into and from the aggregated medical data databases 7011 for the operations of the applications 7014. The caches 7018 also store data (e.g., temporarily) and are coupled to the APIs 7016 for more efficient retrieval of data used by the applications 7014. The data analytics modules 7034 in FIG. 13 include modules for resource optimization 7020, data collection and aggregation 7022, authorization and security 7024, control program updating 7026, patient outcome analysis 7028, recommendations 7030, and data sorting and prioritization 7032. Other suitable data analytics modules could also be implemented by the cloud 7004, according to some aspects. In one aspect, the data analytics modules are used for specific recommendations based on analyzing trends, outcomes, and other data.

For example, the data collection and aggregation module 7022 could be used to generate self-describing data (e.g., metadata) including identification of notable features or configuration (e.g., trends), management of redundant data sets, and storage of the data in paired data sets which can be grouped by surgery but not necessarily keyed to actual surgical dates and surgeons. In particular, pair data sets generated from operations of surgical instruments 7012 can comprise applying a binary classification, e.g., a bleeding or a non-bleeding event. More generally, the binary classification may be characterized as either a desirable event (e.g., a successful surgical procedure) or an undesirable event (e.g., a misfired or misused surgical instrument 7012). The aggregated self-describing data may correspond to individual data received from various groups or subgroups of surgical hubs 7006. Accordingly, the data collection and aggregation module 7022 can generate aggregated metadata or other organized data based on raw data received from the surgical hubs 7006. To this end, the processors 7008 can be operationally coupled to the hub applications 7014 and aggregated medical data databases 7011 for executing the data analytics modules 7034. The data collection and aggregation module 7022 may store the aggregated organized data into the aggregated medical data databases 2212.

The resource optimization module 7020 can be configured to analyze this aggregated data to determine an optimal usage of resources for a particular or group of healthcare facilities. For example, the resource optimization module 7020 may determine an optimal order point of surgical stapling instruments 7012 for a group of healthcare facilities based on corresponding predicted demand of such instruments 7012. The resource optimization module 7020 might also assess the resource usage or other operational configurations of various healthcare facilities to determine whether resource usage could be improved. Similarly, the recommendations module 7030 can be configured to analyze aggregated organized data from the data collection and aggregation module 7022 to provide recommendations. For example, the recommendations module 7030 could recommend to healthcare facilities (e.g., medical service providers such as hospitals) that a particular surgical instrument 7012 should be upgraded to an improved version based on a higher than expected error rate, for example. Additionally, the recommendations module 7030 and/or resource optimization module 7020 could recommend better supply chain parameters such as product reorder points and provide suggestions of different surgical instrument 7012, uses thereof, or procedure steps to improve surgical outcomes. The healthcare facilities can receive such recommendations via corresponding surgical hubs 7006. More specific recommendations regarding parameters or configurations of various surgical instruments 7012 can also be provided. Hubs 7006 and/or surgical instruments 7012 each could also have display screens that display data or recommendations provided by the cloud 7004.

The patient outcome analysis module 7028 can analyze surgical outcomes associated with currently used operational parameters of surgical instruments 7012. The patient outcome analysis module 7028 may also analyze and assess other potential operational parameters. In this connection, the recommendations module 7030 could recommend using these other potential operational parameters based on yielding better surgical outcomes, such as better sealing or less bleeding. For example, the recommendations module 7030 could transmit recommendations to a surgical hub 7006 regarding when to use a particular cartridge for a corresponding stapling surgical instrument 7012. Thus, the cloud-based analytics system, while controlling for common variables, may be configured to analyze the large collection of raw data and to provide centralized recommendations over multiple healthcare facilities (advantageously determined based on aggregated data). For example, the cloud-based analytics system could analyze, evaluate, and/or aggregate data based on type of medical practice, type of patient, number of patients, geographic similarity between medical providers, which medical providers/facilities use similar types of instruments, etc., in a way that no single healthcare facility alone would be able to analyze independently.

The control program updating module 7026 could be configured to implement various surgical instrument 7012 recommendations when corresponding control programs are updated. For example, the patient outcome analysis module 7028 could identify correlations linking specific control parameters with successful (or unsuccessful) results. Such correlations may be addressed when updated control programs are transmitted to surgical instruments 7012 via the control program updating module 7026. Updates to instruments 7012 that are transmitted via a corresponding hub 7006 may incorporate aggregated performance data that was gathered and analyzed by the data collection and aggregation module 7022 of the cloud 7004. Additionally, the patient outcome analysis module 7028 and recommendations module 7030 could identify improved methods of using instruments 7012 based on aggregated performance data.

The cloud-based analytics system may include security features implemented by the cloud 7004. These security features may be managed by the authorization and security module 7024. Each surgical hub 7006 can have associated unique credentials such as username, password, and other suitable security credentials. These credentials could be stored in the memory 7010 and be associated with a permitted cloud access level. For example, based on providing accurate credentials, a surgical hub 7006 may be granted access to communicate with the cloud to a predetermined extent (e.g., may only engage in transmitting or receiving certain defined types of information). To this end, the aggregated medical data databases 7011 of the cloud 7004 may comprise a database of authorized credentials for verifying the accuracy of provided credentials. Different credentials may be associated with varying levels of permission for interaction with the cloud 7004, such as a predetermined access level for receiving the data analytics generated by the cloud 7004.

Furthermore, for security purposes, the cloud could maintain a database of hubs 7006, instruments 7012, and other devices that may comprise a “black list” of prohibited devices. In particular, a surgical hub 7006 listed on the black list may not be permitted to interact with the cloud, while surgical instruments 7012 listed on the black list may not have functional access to a corresponding hub 7006 and/or may be prevented from fully functioning when paired to its corresponding hub 7006. Additionally or alternatively, the cloud 7004 may flag instruments 7012 based on incompatibility or other specified criteria. In this manner, counterfeit medical devices and improper reuse of such devices throughout the cloud-based analytics system can be identified and addressed.

The surgical instruments 7012 may use wireless transceivers to transmit wireless signals that may represent, for example, authorization credentials for access to corresponding hubs 7006 and the cloud 7004. Wired transceivers may also be used to transmit signals. Such authorization credentials can be stored in the respective memory devices of the surgical instruments 7012. The authorization and security module 7024 can determine whether the authorization credentials are accurate or counterfeit. The authorization and security module 7024 may also dynamically generate authorization credentials for enhanced security. The credentials could also be encrypted, such as by using hash based encryption. Upon transmitting proper authorization, the surgical instruments 7012 may transmit a signal to the corresponding hubs 7006 and ultimately the cloud 7004 to indicate that the instruments 7012 are ready to obtain and transmit medical data. In response, the cloud 7004 may transition into a state enabled for receiving medical data for storage into the aggregated medical data databases 7011. This data transmission readiness could be indicated by a light indicator on the instruments 7012, for example. The cloud 7004 can also transmit signals to surgical instruments 7012 for updating their associated control programs. The cloud 7004 can transmit signals that are directed to a particular class of surgical instruments 7012 (e.g., electrosurgical instruments) so that software updates to control programs are only transmitted to the appropriate surgical instruments 7012. Moreover, the cloud 7004 could be used to implement system wide solutions to address local or global problems based on selective data transmission and authorization credentials. For example, if a group of surgical instruments 7012 are identified as having a common manufacturing defect, the cloud 7004 may change the authorization credentials corresponding to this group to implement an operational lockout of the group.

The cloud-based analytics system may allow for monitoring multiple healthcare facilities (e.g., medical facilities like hospitals) to determine improved practices and recommend changes (via the recommendations module 2030, for example) accordingly. Thus, the processors 7008 of the cloud 7004 can analyze data associated with an individual healthcare facility to identify the facility and aggregate the data with other data associated with other healthcare facilities in a group. Groups could be defined based on similar operating practices or geographical location, for example. In this way, the cloud 7004 may provide healthcare facility group wide analysis and recommendations. The cloud-based analytics system could also be used for enhanced situational awareness. For example, the processors 7008 may predictively model the effects of recommendations on the cost and effectiveness for a particular facility (relative to overall operations and/or various medical procedures). The cost and effectiveness associated with that particular facility can also be compared to a corresponding local region of other facilities or any other comparable facilities.

The data sorting and prioritization module 7032 may prioritize and sort data based on criticality (e.g., the severity of a medical event associated with the data, unexpectedness, suspiciousness). This sorting and prioritization may be used in conjunction with the functions of the other data analytics modules 7034 described above to improve the cloud-based analytics and operations described herein. For example, the data sorting and prioritization module 7032 can assign a priority to the data analysis performed by the data collection and aggregation module 7022 and patient outcome analysis modules 7028. Different prioritization levels can result in particular responses from the cloud 7004 (corresponding to a level of urgency) such as escalation for an expedited response, special processing, exclusion from the aggregated medical data databases 7011, or other suitable responses. Moreover, if necessary, the cloud 7004 can transmit a request (e.g. a push message) through the hub application servers for additional data from corresponding surgical instruments 7012. The push message can result in a notification displayed on the corresponding hubs 7006 for requesting supporting or additional data. This push message may be required in situations in which the cloud detects a significant irregularity or outlier and the cloud cannot determine the cause of the irregularity. The central servers 7013 may be programmed to trigger this push message in certain significant circumstances, such as when data is determined to be different from an expected value beyond a predetermined threshold or when it appears security has been comprised, for example.

Additional details regarding the cloud analysis system can be found in U.S. Provisional Patent Application No. 62/659,900, titled METHOD OF HUB COMMUNICATION, filed Apr. 19, 2018, which is hereby incorporated by reference herein in its entirety.

Situational Awareness

Although an “intelligent” device including control algorithms that respond to sensed data can be an improvement over a “dumb” device that operates without accounting for sensed data, some sensed data can be incomplete or inconclusive when considered in isolation, i.e., without the context of the type of surgical procedure being performed or the type of tissue that is being operated on. Without knowing the procedural context (e.g., knowing the type of tissue being operated on or the type of procedure being performed), the control algorithm may control the modular device incorrectly or suboptimally given the particular context-free sensed data. For example, the optimal manner for a control algorithm to control a surgical instrument in response to a particular sensed parameter can vary according to the particular tissue type being operated on. This is due to the fact that different tissue types have different properties (e.g., resistance to tearing) and thus respond differently to actions taken by surgical instruments. Therefore, it may be desirable for a surgical instrument to take different actions even when the same measurement for a particular parameter is sensed. As one specific example, the optimal manner in which to control a surgical stapling and cutting instrument in response to the instrument sensing an unexpectedly high force to close its end effector will vary depending upon whether the tissue type is susceptible or resistant to tearing. For tissues that are susceptible to tearing, such as lung tissue, the instrument's control algorithm would optimally ramp down the motor in response to an unexpectedly high force to close to avoid tearing the tissue. For tissues that are resistant to tearing, such as stomach tissue, the instrument's control algorithm would optimally ramp up the motor in response to an unexpectedly high force to close to ensure that the end effector is clamped properly on the tissue. Without knowing whether lung or stomach tissue has been clamped, the control algorithm may make a suboptimal decision.

One solution utilizes a surgical hub including a system that is configured to derive information about the surgical procedure being performed based on data received from various data sources and then control the paired modular devices accordingly. In other words, the surgical hub is configured to infer information about the surgical procedure from received data and then control the modular devices paired to the surgical hub based upon the inferred context of the surgical procedure. FIG. 14 illustrates a diagram of a situationally aware surgical system 5100, in accordance with at least one aspect of the present disclosure. In some exemplifications, the data sources 5126 include, for example, the modular devices 5102 (which can include sensors configured to detect parameters associated with the patient and/or the modular device itself), databases 5122 (e.g., an EMR database containing patient records), and patient monitoring devices 5124 (e.g., a blood pressure (BP) monitor and an electrocardiography (EKG) monitor).

A surgical hub 5104, which may be similar to the hub 106 in many respects, can be configured to derive the contextual information pertaining to the surgical procedure from the data based upon, for example, the particular combination(s) of received data or the particular order in which the data is received from the data sources 5126. The contextual information inferred from the received data can include, for example, the type of surgical procedure being performed, the particular step of the surgical procedure that the surgeon is performing, the type of tissue being operated on, or the body cavity that is the subject of the procedure. This ability by some aspects of the surgical hub 5104 to derive or infer information related to the surgical procedure from received data can be referred to as “situational awareness.” In one exemplification, the surgical hub 5104 can incorporate a situational awareness system, which is the hardware and/or programming associated with the surgical hub 5104 that derives contextual information pertaining to the surgical procedure from the received data.

The situational awareness system of the surgical hub 5104 can be configured to derive the contextual information from the data received from the data sources 5126 in a variety of different ways. In one exemplification, the situational awareness system includes a pattern recognition system, or machine learning system (e.g., an artificial neural network), that has been trained on training data to correlate various inputs (e.g., data from databases 5122, patient monitoring devices 5124, and/or modular devices 5102) to corresponding contextual information regarding a surgical procedure. In other words, a machine learning system can be trained to accurately derive contextual information regarding a surgical procedure from the provided inputs. In another exemplification, the situational awareness system can include a lookup table storing pre-characterized contextual information regarding a surgical procedure in association with one or more inputs (or ranges of inputs) corresponding to the contextual information. In response to a query with one or more inputs, the lookup table can return the corresponding contextual information for the situational awareness system for controlling the modular devices 5102. In one exemplification, the contextual information received by the situational awareness system of the surgical hub 5104 is associated with a particular control adjustment or set of control adjustments for one or more modular devices 5102. In another exemplification, the situational awareness system includes a further machine learning system, lookup table, or other such system, which generates or retrieves one or more control adjustments for one or more modular devices 5102 when provided the contextual information as input.

A surgical hub 5104 incorporating a situational awareness system provides a number of benefits for the surgical system 5100. One benefit includes improving the interpretation of sensed and collected data, which would in turn improve the processing accuracy and/or the usage of the data during the course of a surgical procedure. To return to a previous example, a situationally aware surgical hub 5104 could determine what type of tissue was being operated on; therefore, when an unexpectedly high force to close the surgical instrument's end effector is detected, the situationally aware surgical hub 5104 could correctly ramp up or ramp down the motor of the surgical instrument for the type of tissue.

As another example, the type of tissue being operated can affect the adjustments that are made to the compression rate and load thresholds of a surgical stapling and cutting instrument for a particular tissue gap measurement. A situationally aware surgical hub 5104 could infer whether a surgical procedure being performed is a thoracic or an abdominal procedure, allowing the surgical hub 5104 to determine whether the tissue clamped by an end effector of the surgical stapling and cutting instrument is lung (for a thoracic procedure) or stomach (for an abdominal procedure) tissue. The surgical hub 5104 could then adjust the compression rate and load thresholds of the surgical stapling and cutting instrument appropriately for the type of tissue.

As yet another example, the type of body cavity being operated in during an insufflation procedure can affect the function of a smoke evacuator. A situationally aware surgical hub 5104 could determine whether the surgical site is under pressure (by determining that the surgical procedure is utilizing insufflation) and determine the procedure type. As a procedure type is generally performed in a specific body cavity, the surgical hub 5104 could then control the motor rate of the smoke evacuator appropriately for the body cavity being operated in. Thus, a situationally aware surgical hub 5104 could provide a consistent amount of smoke evacuation for both thoracic and abdominal procedures.

As yet another example, the type of procedure being performed can affect the optimal energy level for an ultrasonic surgical instrument or radio frequency (RF) electrosurgical instrument to operate at. Arthroscopic procedures, for example, require higher energy levels because the end effector of the ultrasonic surgical instrument or RF electrosurgical instrument is immersed in fluid. A situationally aware surgical hub 5104 could determine whether the surgical procedure is an arthroscopic procedure. The surgical hub 5104 could then adjust the RF power level or the ultrasonic amplitude of the generator (i.e., “energy level”) to compensate for the fluid filled environment. Relatedly, the type of tissue being operated on can affect the optimal energy level for an ultrasonic surgical instrument or RF electrosurgical instrument to operate at. A situationally aware surgical hub 5104 could determine what type of surgical procedure is being performed and then customize the energy level for the ultrasonic surgical instrument or RF electrosurgical instrument, respectively, according to the expected tissue profile for the surgical procedure. Furthermore, a situationally aware surgical hub 5104 can be configured to adjust the energy level for the ultrasonic surgical instrument or RF electrosurgical instrument throughout the course of a surgical procedure, rather than just on a procedure-by-procedure basis. A situationally aware surgical hub 5104 could determine what step of the surgical procedure is being performed or will subsequently be performed and then update the control algorithms for the generator and/or ultrasonic surgical instrument or RF electrosurgical instrument to set the energy level at a value appropriate for the expected tissue type according to the surgical procedure step.

As yet another example, data can be drawn from additional data sources 5126 to improve the conclusions that the surgical hub 5104 draws from one data source 5126. A situationally aware surgical hub 5104 could augment data that it receives from the modular devices 5102 with contextual information that it has built up regarding the surgical procedure from other data sources 5126. For example, a situationally aware surgical hub 5104 can be configured to determine whether hemostasis has occurred (i.e., whether bleeding at a surgical site has stopped) according to video or image data received from a medical imaging device. However, in some cases the video or image data can be inconclusive. Therefore, in one exemplification, the surgical hub 5104 can be further configured to compare a physiologic measurement (e.g., blood pressure sensed by a BP monitor communicably connected to the surgical hub 5104) with the visual or image data of hemostasis (e.g., from a medical imaging device 124 (FIG. 2) communicably coupled to the surgical hub 5104) to make a determination on the integrity of the staple line or tissue weld. In other words, the situational awareness system of the surgical hub 5104 can consider the physiological measurement data to provide additional context in analyzing the visualization data. The additional context can be useful when the visualization data may be inconclusive or incomplete on its own.

Another benefit includes proactively and automatically controlling the paired modular devices 5102 according to the particular step of the surgical procedure that is being performed to reduce the number of times that medical personnel are required to interact with or control the surgical system 5100 during the course of a surgical procedure. For example, a situationally aware surgical hub 5104 could proactively activate the generator to which an RF electrosurgical instrument is connected if it determines that a subsequent step of the procedure requires the use of the instrument. Proactively activating the energy source allows the instrument to be ready for use a soon as the preceding step of the procedure is completed.

As another example, a situationally aware surgical hub 5104 could determine whether the current or subsequent step of the surgical procedure requires a different view or degree of magnification on the display according to the feature(s) at the surgical site that the surgeon is expected to need to view. The surgical hub 5104 could then proactively change the displayed view (supplied by, e.g., a medical imaging device for the visualization system 108) accordingly so that the display automatically adjusts throughout the surgical procedure.

As yet another example, a situationally aware surgical hub 5104 could determine which step of the surgical procedure is being performed or will subsequently be performed and whether particular data or comparisons between data will be required for that step of the surgical procedure. The surgical hub 5104 can be configured to automatically call up data screens based upon the step of the surgical procedure being performed, without waiting for the surgeon to ask for the particular information.

Another benefit includes checking for errors during the setup of the surgical procedure or during the course of the surgical procedure. For example, a situationally aware surgical hub 5104 could determine whether the operating theater is setup properly or optimally for the surgical procedure to be performed. The surgical hub 5104 can be configured to determine the type of surgical procedure being performed, retrieve the corresponding checklists, product location, or setup needs (e.g., from a memory), and then compare the current operating theater layout to the standard layout for the type of surgical procedure that the surgical hub 5104 determines is being performed. In one exemplification, the surgical hub 5104 can be configured to compare the list of items for the procedure scanned by a suitable scanner, for example, and/or a list of devices paired with the surgical hub 5104 to a recommended or anticipated manifest of items and/or devices for the given surgical procedure. If there are any discontinuities between the lists, the surgical hub 5104 can be configured to provide an alert indicating that a particular modular device 5102, patient monitoring device 5124, and/or other surgical item is missing. In one exemplification, the surgical hub 5104 can be configured to determine the relative distance or position of the modular devices 5102 and patient monitoring devices 5124 via proximity sensors, for example. The surgical hub 5104 can compare the relative positions of the devices to a recommended or anticipated layout for the particular surgical procedure. If there are any discontinuities between the layouts, the surgical hub 5104 can be configured to provide an alert indicating that the current layout for the surgical procedure deviates from the recommended layout.

As another example, a situationally aware surgical hub 5104 could determine whether the surgeon (or other medical personnel) was making an error or otherwise deviating from the expected course of action during the course of a surgical procedure. For example, the surgical hub 5104 can be configured to determine the type of surgical procedure being performed, retrieve the corresponding list of steps or order of equipment usage (e.g., from a memory), and then compare the steps being performed or the equipment being used during the course of the surgical procedure to the expected steps or equipment for the type of surgical procedure that the surgical hub 5104 determined is being performed. In one exemplification, the surgical hub 5104 can be configured to provide an alert indicating that an unexpected action is being performed or an unexpected device is being utilized at the particular step in the surgical procedure.

Overall, the situational awareness system for the surgical hub 5104 improves surgical procedure outcomes by adjusting the surgical instruments (and other modular devices 5102) for the particular context of each surgical procedure (such as adjusting to different tissue types) and validating actions during a surgical procedure. The situational awareness system also improves surgeons' efficiency in performing surgical procedures by automatically suggesting next steps, providing data, and adjusting displays and other modular devices 5102 in the surgical theater according to the specific context of the procedure.

Referring now to FIG. 15, a timeline 5200 depicting situational awareness of a hub, such as the surgical hub 106 or 206 (FIGS. 1-11), for example, is depicted. The timeline 5200 is an illustrative surgical procedure and the contextual information that the surgical hub 106,206 can derive from the data received from the data sources at each step in the surgical procedure. The timeline 5200 depicts the typical steps that would be taken by the nurses, surgeons, and other medical personnel during the course of a lung segmentectomy procedure, beginning with setting up the operating theater and ending with transferring the patient to a post-operative recovery room.

The situationally aware surgical hub 106, 206 receives data from the data sources throughout the course of the surgical procedure, including data generated each time medical personnel utilize a modular device that is paired with the surgical hub 106, 206. The surgical hub 106, 206 can receive this data from the paired modular devices and other data sources and continually derive inferences (i.e., contextual information) about the ongoing procedure as new data is received, such as which step of the procedure is being performed at any given time. The situational awareness system of the surgical hub 106, 206 is able to, for example, record data pertaining to the procedure for generating reports, verify the steps being taken by the medical personnel, provide data or prompts (e.g., via a display screen) that may be pertinent for the particular procedural step, adjust modular devices based on the context (e.g., activate monitors, adjust the field of view (FOV) of the medical imaging device, or change the energy level of an ultrasonic surgical instrument or RF electrosurgical instrument), and take any other such action described above.

As the first step 5202 in this illustrative procedure, the hospital staff members retrieve the patient's EMR from the hospital's EMR database. Based on select patient data in the EMR, the surgical hub 106, 206 determines that the procedure to be performed is a thoracic procedure.

Second step 5204, the staff members scan the incoming medical supplies for the procedure. The surgical hub 106, 206 cross-references the scanned supplies with a list of supplies that are utilized in various types of procedures and confirms that the mix of supplies corresponds to a thoracic procedure. Further, the surgical hub 106, 206 is also able to determine that the procedure is not a wedge procedure (because the incoming supplies either lack certain supplies that are necessary for a thoracic wedge procedure or do not otherwise correspond to a thoracic wedge procedure).

Third step 5206, the medical personnel scan the patient band via a scanner that is communicably connected to the surgical hub 106, 206. The surgical hub 106, 206 can then confirm the patient's identity based on the scanned data.

Fourth step 5208, the medical staff turns on the auxiliary equipment. The auxiliary equipment being utilized can vary according to the type of surgical procedure and the techniques to be used by the surgeon, but in this illustrative case they include a smoke evacuator, insufflator, and medical imaging device. When activated, the auxiliary equipment that are modular devices can automatically pair with the surgical hub 106, 206 that is located within a particular vicinity of the modular devices as part of their initialization process. The surgical hub 106, 206 can then derive contextual information about the surgical procedure by detecting the types of modular devices that pair with it during this pre-operative or initialization phase. In this particular example, the surgical hub 106, 206 determines that the surgical procedure is a VATS procedure based on this particular combination of paired modular devices. Based on the combination of the data from the patient's EMR, the list of medical supplies to be used in the procedure, and the type of modular devices that connect to the hub, the surgical hub 106, 206 can generally infer the specific procedure that the surgical team will be performing. Once the surgical hub 106, 206 knows what specific procedure is being performed, the surgical hub 106, 206 can then retrieve the steps of that procedure from a memory or from the cloud and then cross-reference the data it subsequently receives from the connected data sources (e.g., modular devices and patient monitoring devices) to infer what step of the surgical procedure the surgical team is performing.

Fifth step 5210, the staff members attach the EKG electrodes and other patient monitoring devices to the patient. The EKG electrodes and other patient monitoring devices are able to pair with the surgical hub 106, 206. As the surgical hub 106, 206 begins receiving data from the patient monitoring devices, the surgical hub 106, 206 thus confirms that the patient is in the operating theater.

Sixth step 5212, the medical personnel induce anesthesia in the patient. The surgical hub 106, 206 can infer that the patient is under anesthesia based on data from the modular devices and/or patient monitoring devices, including EKG data, blood pressure data, ventilator data, or combinations thereof, for example. Upon completion of the sixth step 5212, the pre-operative portion of the lung segmentectomy procedure is completed and the operative portion begins.

Seventh step 5214, the patient's lung that is being operated on is collapsed (while ventilation is switched to the contralateral lung). The surgical hub 106, 206 can infer from the ventilator data that the patient's lung has been collapsed, for example. The surgical hub 106, 206 can infer that the operative portion of the procedure has commenced as it can compare the detection of the patient's lung collapsing to the expected steps of the procedure (which can be accessed or retrieved previously) and thereby determine that collapsing the lung is the first operative step in this particular procedure.

Eighth step 5216, the medical imaging device (e.g., a scope) is inserted and video from the medical imaging device is initiated. The surgical hub 106, 206 receives the medical imaging device data (i.e., video or image data) through its connection to the medical imaging device. Upon receipt of the medical imaging device data, the surgical hub 106, 206 can determine that the laparoscopic portion of the surgical procedure has commenced. Further, the surgical hub 106, 206 can determine that the particular procedure being performed is a segmentectomy, as opposed to a lobectomy (note that a wedge procedure has already been discounted by the surgical hub 106, 206 based on data received at the second step 5204 of the procedure). The data from the medical imaging device 124 (FIG. 2) can be utilized to determine contextual information regarding the type of procedure being performed in a number of different ways, including by determining the angle at which the medical imaging device is oriented with respect to the visualization of the patient's anatomy, monitoring the number or medical imaging devices being utilized (i.e., that are activated and paired with the surgical hub 106, 206), and monitoring the types of visualization devices utilized. For example, one technique for performing a VATS lobectomy places the camera in the lower anterior corner of the patient's chest cavity above the diaphragm, whereas one technique for performing a VATS segmentectomy places the camera in an anterior intercostal position relative to the segmental fissure. Using pattern recognition or machine learning techniques, for example, the situational awareness system can be trained to recognize the positioning of the medical imaging device according to the visualization of the patient's anatomy. As another example, one technique for performing a VATS lobectomy utilizes a single medical imaging device, whereas another technique for performing a VATS segmentectomy utilizes multiple cameras. As yet another example, one technique for performing a VATS segmentectomy utilizes an infrared light source (which can be communicably coupled to the surgical hub as part of the visualization system) to visualize the segmental fissure, which is not utilized in a VATS lobectomy. By tracking any or all of this data from the medical imaging device, the surgical hub 106, 206 can thereby determine the specific type of surgical procedure being performed and/or the technique being used for a particular type of surgical procedure.

Ninth step 5218, the surgical team begins the dissection step of the procedure. The surgical hub 106, 206 can infer that the surgeon is in the process of dissecting to mobilize the patient's lung because it receives data from the RF or ultrasonic generator indicating that an energy instrument is being fired. The surgical hub 106, 206 can cross-reference the received data with the retrieved steps of the surgical procedure to determine that an energy instrument being fired at this point in the process (i.e., after the completion of the previously discussed steps of the procedure) corresponds to the dissection step. In certain instances, the energy instrument can be an energy tool mounted to a robotic arm of a robotic surgical system.

Tenth step 5220, the surgical team proceeds to the ligation step of the procedure. The surgical hub 106, 206 can infer that the surgeon is ligating arteries and veins because it receives data from the surgical stapling and cutting instrument indicating that the instrument is being fired. Similarly to the prior step, the surgical hub 106, 206 can derive this inference by cross-referencing the receipt of data from the surgical stapling and cutting instrument with the retrieved steps in the process. In certain instances, the surgical instrument can be a surgical tool mounted to a robotic arm of a robotic surgical system.

Eleventh step 5222, the segmentectomy portion of the procedure is performed. The surgical hub 106, 206 can infer that the surgeon is transecting the parenchyma based on data from the surgical stapling and cutting instrument, including data from its cartridge. The cartridge data can correspond to the size or type of staple being fired by the instrument, for example. As different types of staples are utilized for different types of tissues, the cartridge data can thus indicate the type of tissue being stapled and/or transected. In this case, the type of staple being fired is utilized for parenchyma (or other similar tissue types), which allows the surgical hub 106, 206 to infer that the segmentectomy portion of the procedure is being performed.

Twelfth step 5224, the node dissection step is then performed. The surgical hub 106, 206 can infer that the surgical team is dissecting the node and performing a leak test based on data received from the generator indicating that an RF or ultrasonic instrument is being fired. For this particular procedure, an RF or ultrasonic instrument being utilized after parenchyma was transected corresponds to the node dissection step, which allows the surgical hub 106, 206 to make this inference. It should be noted that surgeons regularly switch back and forth between surgical stapling/cutting instruments and surgical energy (i.e., RF or ultrasonic) instruments depending upon the particular step in the procedure because different instruments are better adapted for particular tasks. Therefore, the particular sequence in which the stapling/cutting instruments and surgical energy instruments are used can indicate what step of the procedure the surgeon is performing. Moreover, in certain instances, robotic tools can be utilized for one or more steps in a surgical procedure and/or handheld surgical instruments can be utilized for one or more steps in the surgical procedure. The surgeon(s) can alternate between robotic tools and handheld surgical instruments and/or can use the devices concurrently, for example. Upon completion of the twelfth step 5224, the incisions are closed up and the post-operative portion of the procedure begins.

Thirteenth step 5226, the patient's anesthesia is reversed. The surgical hub 106, 206 can infer that the patient is emerging from the anesthesia based on the ventilator data (i.e., the patient's breathing rate begins increasing), for example.

Lastly, the fourteenth step 5228 is that the medical personnel remove the various patient monitoring devices from the patient. The surgical hub 106, 206 can thus infer that the patient is being transferred to a recovery room when the hub loses EKG, BP, and other data from the patient monitoring devices. As can be seen from the description of this illustrative procedure, the surgical hub 106, 206 can determine or infer when each step of a given surgical procedure is taking place according to data received from the various data sources that are communicably coupled to the surgical hub 106, 206.

Situational awareness is further described in U.S. Provisional Patent Application Ser. No. 62/659,900, titled METHOD OF HUB COMMUNICATION, filed Apr. 19, 2018, which is herein incorporated by reference in its entirety. In certain instances, operation of a robotic surgical system, including the various robotic surgical systems disclosed herein, for example, can be controlled by the hub 106, 206 based on its situational awareness and/or feedback from the components thereof and/or based on information from the cloud 104.

In one aspect, as described hereinbelow with reference to FIGS. 1-22, the modular device 5102 is implemented as ultrasonic surgical instruments and combination energy surgical instruments 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F. Accordingly, the modular device 5102 implemented as a ultrasonic surgical instrument and combination energy surgical instrument 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F is configured to operate as a data source 5126 and to interact with the database 5122 and patient monitoring devices 5124. The modular device 5102 implemented as a ultrasonic surgical instrument and combination energy surgical instrument 7012 as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F is further configured to interact with the surgical hub 5104 to provide information (e.g., data and control) to the surgical hub 5104 and receive information (e.g., data and control) from the surgical hub 5104.

Generator Hardware

FIG. 16 is a schematic diagram of a robotic surgical instrument 700 configured to operate a surgical tool described herein according to one aspect of this disclosure. The robotic surgical instrument 700 may be programmed or configured to control distal/proximal translation of a displacement member, distal/proximal displacement of a closure tube, shaft rotation, and articulation, either with single or multiple articulation drive links. In one aspect, the surgical instrument 700 may be programmed or configured to individually control a firing member, a closure member, a shaft member, or one or more articulation members, or combinations thereof. The surgical instrument 700 comprises a control circuit 710 configured to control motor-driven firing members, closure members, shaft members, or one or more articulation members, or combinations thereof.

In one aspect, the robotic surgical instrument 700 comprises a control circuit 710 configured to control a clamp arm 716 and a closure member 714 portion of an end effector 702, an ultrasonic blade 718 coupled to an ultrasonic transducer 719 excited by an ultrasonic generator 721, a shaft 740, and one or more articulation members 742 a, 742 b via a plurality of motors 704 a-704 e. A position sensor 734 may be configured to provide position feedback of the closure member 714 to the control circuit 710. Other sensors 738 may be configured to provide feedback to the control circuit 710. A timer/counter 731 provides timing and counting information to the control circuit 710. An energy source 712 may be provided to operate the motors 704 a-704 e, and a current sensor 736 provides motor current feedback to the control circuit 710. The motors 704 a-704 e can be operated individually by the control circuit 710 in an open-loop or closed-loop feedback control.

In one aspect, the control circuit 710 may comprise one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the processor or processors to perform one or more tasks. In one aspect, a timer/counter 731 provides an output signal, such as the elapsed time or a digital count, to the control circuit 710 to correlate the position of the closure member 714 as determined by the position sensor 734 with the output of the timer/counter 731 such that the control circuit 710 can determine the position of the closure member 714 at a specific time (t) relative to a starting position or the time (t) when the closure member 714 is at a specific position relative to a starting position. The timer/counter 731 may be configured to measure elapsed time, count external events, or time external events.

In one aspect, the control circuit 710 may be programmed to control functions of the end effector 702 based on one or more tissue conditions. The control circuit 710 may be programmed to sense tissue conditions, such as thickness, either directly or indirectly, as described herein. The control circuit 710 may be programmed to select a firing control program or closure control program based on tissue conditions. A firing control program may describe the distal motion of the displacement member. Different firing control programs may be selected to better treat different tissue conditions. For example, when thicker tissue is present, the control circuit 710 may be programmed to translate the displacement member at a lower velocity and/or with lower power. When thinner tissue is present, the control circuit 710 may be programmed to translate the displacement member at a higher velocity and/or with higher power. A closure control program may control the closure force applied to the tissue by the clamp arm 716. Other control programs control the rotation of the shaft 740 and the articulation members 742 a, 742 b.

In one aspect, the control circuit 710 may generate motor set point signals. The motor set point signals may be provided to various motor controllers 708 a-708 e. The motor controllers 708 a-708 e may comprise one or more circuits configured to provide motor drive signals to the motors 704 a-704 e to drive the motors 704 a-704 e as described herein. In some examples, the motors 704 a-704 e may be brushed DC electric motors. For example, the velocity of the motors 704 a-704 e may be proportional to the respective motor drive signals. In some examples, the motors 704 a-704 e may be brushless DC electric motors, and the respective motor drive signals may comprise a PWM signal provided to one or more stator windings of the motors 704 a-704 e. Also, in some examples, the motor controllers 708 a-708 e may be omitted and the control circuit 710 may generate the motor drive signals directly.

In one aspect, the control circuit 710 may initially operate each of the motors 704 a-704 e in an open-loop configuration for a first open-loop portion of a stroke of the displacement member. Based on the response of the robotic surgical instrument 700 during the open-loop portion of the stroke, the control circuit 710 may select a firing control program in a closed-loop configuration. The response of the instrument may include a translation distance of the displacement member during the open-loop portion, a time elapsed during the open-loop portion, the energy provided to one of the motors 704 a-704 e during the open-loop portion, a sum of pulse widths of a motor drive signal, etc. After the open-loop portion, the control circuit 710 may implement the selected firing control program for a second portion of the displacement member stroke. For example, during a closed-loop portion of the stroke, the control circuit 710 may modulate one of the motors 704 a-704 e based on translation data describing a position of the displacement member in a closed-loop manner to translate the displacement member at a constant velocity.

In one aspect, the motors 704 a-704 e may receive power from an energy source 712. The energy source 712 may be a DC power supply driven by a main alternating current power source, a battery, a super capacitor, or any other suitable energy source. The motors 704 a-704 e may be mechanically coupled to individual movable mechanical elements such as the closure member 714, clamp arm 716, shaft 740, articulation 742 a, and articulation 742 b via respective transmissions 706 a-706 e. The transmissions 706 a-706 e may include one or more gears or other linkage components to couple the motors 704 a-704 e to movable mechanical elements. A position sensor 734 may sense a position of the closure member 714. The position sensor 734 may be or include any type of sensor that is capable of generating position data that indicate a position of the closure member 714. In some examples, the position sensor 734 may include an encoder configured to provide a series of pulses to the control circuit 710 as the closure member 714 translates distally and proximally. The control circuit 710 may track the pulses to determine the position of the closure member 714. Other suitable position sensors may be used, including, for example, a proximity sensor. Other types of position sensors may provide other signals indicating motion of the closure member 714. Also, in some examples, the position sensor 734 may be omitted. Where any of the motors 704 a-704 e is a stepper motor, the control circuit 710 may track the position of the closure member 714 by aggregating the number and direction of steps that the motor 704 has been instructed to execute. The position sensor 734 may be located in the end effector 702 or at any other portion of the instrument. The outputs of each of the motors 704 a-704 e include a torque sensor 744 a-744 e to sense force and have an encoder to sense rotation of the drive shaft.

In one aspect, the control circuit 710 is configured to drive a firing member such as the closure member 714 portion of the end effector 702. The control circuit 710 provides a motor set point to a motor control 708 a, which provides a drive signal to the motor 704 a. The output shaft of the motor 704 a is coupled to a torque sensor 744 a. The torque sensor 744 a is coupled to a transmission 706 a which is coupled to the closure member 714. The transmission 706 a comprises movable mechanical elements such as rotating elements and a firing member to control the movement of the closure member 714 distally and proximally along a longitudinal axis of the end effector 702. In one aspect, the motor 704 a may be coupled to the knife gear assembly, which includes a knife gear reduction set that includes a first knife drive gear and a second knife drive gear. A torque sensor 744 a provides a firing force feedback signal to the control circuit 710. The firing force signal represents the force required to fire or displace the closure member 714. A position sensor 734 may be configured to provide the position of the closure member 714 along the firing stroke or the position of the firing member as a feedback signal to the control circuit 710. The end effector 702 may include additional sensors 738 configured to provide feedback signals to the control circuit 710. When ready to use, the control circuit 710 may provide a firing signal to the motor control 708 a. In response to the firing signal, the motor 704 a may drive the firing member distally along the longitudinal axis of the end effector 702 from a proximal stroke start position to a stroke end position distal to the stroke start position. As the closure member 714 translates distally, the clamp arm 716 closes towards the ultrasonic blade 718.

In one aspect, the control circuit 710 is configured to drive a closure member such as the clamp arm 716 portion of the end effector 702. The control circuit 710 provides a motor set point to a motor control 708 b, which provides a drive signal to the motor 704 b. The output shaft of the motor 704 b is coupled to a torque sensor 744 b. The torque sensor 744 b is coupled to a transmission 706 b which is coupled to the clamp arm 716. The transmission 706 b comprises movable mechanical elements such as rotating elements and a closure member to control the movement of the clamp arm 716 from the open and closed positions. In one aspect, the motor 704 b is coupled to a closure gear assembly, which includes a closure reduction gear set that is supported in meshing engagement with the closure spur gear. The torque sensor 744 b provides a closure force feedback signal to the control circuit 710. The closure force feedback signal represents the closure force applied to the clamp arm 716. The position sensor 734 may be configured to provide the position of the closure member as a feedback signal to the control circuit 710. Additional sensors 738 in the end effector 702 may provide the closure force feedback signal to the control circuit 710. The pivotable clamp arm 716 is positioned opposite the ultrasonic blade 718. When ready to use, the control circuit 710 may provide a closure signal to the motor control 708 b. In response to the closure signal, the motor 704 b advances a closure member to grasp tissue between the clamp arm 716 and the ultrasonic blade 718.

In one aspect, the control circuit 710 is configured to rotate a shaft member such as the shaft 740 to rotate the end effector 702. The control circuit 710 provides a motor set point to a motor control 708 c, which provides a drive signal to the motor 704 c. The output shaft of the motor 704 c is coupled to a torque sensor 744 c. The torque sensor 744 c is coupled to a transmission 706 c which is coupled to the shaft 740. The transmission 706 c comprises movable mechanical elements such as rotating elements to control the rotation of the shaft 740 clockwise or counterclockwise up to and over 360°. In one aspect, the motor 704 c is coupled to the rotational transmission assembly, which includes a tube gear segment that is formed on (or attached to) the proximal end of the proximal closure tube for operable engagement by a rotational gear assembly that is operably supported on the tool mounting plate. The torque sensor 744 c provides a rotation force feedback signal to the control circuit 710. The rotation force feedback signal represents the rotation force applied to the shaft 740. The position sensor 734 may be configured to provide the position of the closure member as a feedback signal to the control circuit 710. Additional sensors 738 such as a shaft encoder may provide the rotational position of the shaft 740 to the control circuit 710.

In one aspect, the control circuit 710 is configured to articulate the end effector 702. The control circuit 710 provides a motor set point to a motor control 708 d, which provides a drive signal to the motor 704 d. The output shaft of the motor 704 d is coupled to a torque sensor 744 d. The torque sensor 744 d is coupled to a transmission 706 d which is coupled to an articulation member 742 a. The transmission 706 d comprises movable mechanical elements such as articulation elements to control the articulation of the end effector 702±65°. In one aspect, the motor 704 d is coupled to an articulation nut, which is rotatably journaled on the proximal end portion of the distal spine portion and is rotatably driven thereon by an articulation gear assembly. The torque sensor 744 d provides an articulation force feedback signal to the control circuit 710. The articulation force feedback signal represents the articulation force applied to the end effector 702. Sensors 738, such as an articulation encoder, may provide the articulation position of the end effector 702 to the control circuit 710.

In another aspect, the articulation function of the robotic surgical system 700 may comprise two articulation members, or links, 742 a, 742 b. These articulation members 742 a, 742 b are driven by separate disks on the robot interface (the rack) which are driven by the two motors 708 d, 708 e. When the separate firing motor 704 a is provided, each of articulation links 742 a, 742 b can be antagonistically driven with respect to the other link in order to provide a resistive holding motion and a load to the head when it is not moving and to provide an articulation motion as the head is articulated. The articulation members 742 a, 742 b attach to the head at a fixed radius as the head is rotated. Accordingly, the mechanical advantage of the push-and-pull link changes as the head is rotated. This change in the mechanical advantage may be more pronounced with other articulation link drive systems.

In one aspect, the one or more motors 704 a-704 e may comprise a brushed DC motor with a gearbox and mechanical links to a firing member, closure member, or articulation member. Another example includes electric motors 704 a-704 e that operate the movable mechanical elements such as the displacement member, articulation links, closure tube, and shaft. An outside influence is an unmeasured, unpredictable influence of things like tissue, surrounding bodies, and friction on the physical system. Such outside influence can be referred to as drag, which acts in opposition to one of electric motors 704 a-704 e. The outside influence, such as drag, may cause the operation of the physical system to deviate from a desired operation of the physical system.

In one aspect, the position sensor 734 may be implemented as an absolute positioning system. In one aspect, the position sensor 734 may comprise a magnetic rotary absolute positioning system implemented as an AS5055EQFT single-chip magnetic rotary position sensor available from Austria Microsystems, AG. The position sensor 734 may interface with the control circuit 710 to provide an absolute positioning system. The position may include multiple Hall-effect elements located above a magnet and coupled to a CORDIC processor, also known as the digit-by-digit method and Volder's algorithm, that is provided to implement a simple and efficient algorithm to calculate hyperbolic and trigonometric functions that require only addition, subtraction, bitshift, and table lookup operations.

In one aspect, the control circuit 710 may be in communication with one or more sensors 738. The sensors 738 may be positioned on the end effector 702 and adapted to operate with the robotic surgical instrument 700 to measure the various derived parameters such as the gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors 738 may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a load cell, a pressure sensor, a force sensor, a torque sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector 702. The sensors 738 may include one or more sensors. The sensors 738 may be located on the clamp arm 716 to determine tissue location using segmented electrodes. The torque sensors 744 a-744 e may be configured to sense force such as firing force, closure force, and/or articulation force, among others. Accordingly, the control circuit 710 can sense (1) the closure load experienced by the distal closure tube and its position, (2) the firing member at the rack and its position, (3) what portion of the ultrasonic blade 718 has tissue on it, and (4) the load and position on both articulation rods.

In one aspect, the one or more sensors 738 may comprise a strain gauge, such as a micro-strain gauge, configured to measure the magnitude of the strain in the clamp arm 716 during a clamped condition. The strain gauge provides an electrical signal whose amplitude varies with the magnitude of the strain. The sensors 738 may comprise a pressure sensor configured to detect a pressure generated by the presence of compressed tissue between the clamp arm 716 and the ultrasonic blade 718. The sensors 738 may be configured to detect impedance of a tissue section located between the clamp arm 716 and the ultrasonic blade 718 that is indicative of the thickness and/or fullness of tissue located therebetween.

In one aspect, the sensors 738 may be implemented as one or more limit switches, electromechanical devices, solid-state switches, Hall-effect devices, magneto-resistive (MR) devices, giant magneto-resistive (GMR) devices, magnetometers, among others. In other implementations, the sensors 738 may be implemented as solid-state switches that operate under the influence of light, such as optical sensors, IR sensors, ultraviolet sensors, among others. Still, the switches may be solid-state devices such as transistors (e.g., FET, junction FET, MOSFET, bipolar, and the like). In other implementations, the sensors 738 may include electrical conductorless switches, ultrasonic switches, accelerometers, and inertial sensors, among others.

In one aspect, the sensors 738 may be configured to measure forces exerted on the clamp arm 716 by the closure drive system. For example, one or more sensors 738 can be at an interaction point between the closure tube and the clamp arm 716 to detect the closure forces applied by the closure tube to the clamp arm 716. The forces exerted on the clamp arm 716 can be representative of the tissue compression experienced by the tissue section captured between the clamp arm 716 and the ultrasonic blade 718. The one or more sensors 738 can be positioned at various interaction points along the closure drive system to detect the closure forces applied to the clamp arm 716 by the closure drive system. The one or more sensors 738 may be sampled in real time during a clamping operation by the processor of the control circuit 710. The control circuit 710 receives real-time sample measurements to provide and analyze time-based information and assess, in real time, closure forces applied to the clamp arm 716.

In one aspect, a current sensor 736 can be employed to measure the current drawn by each of the motors 704 a-704 e. The force required to advance any of the movable mechanical elements such as the closure member 714 corresponds to the current drawn by one of the motors 704 a-704 e. The force is converted to a digital signal and provided to the control circuit 710. The control circuit 710 can be configured to simulate the response of the actual system of the instrument in the software of the controller. A displacement member can be actuated to move the closure member 714 in the end effector 702 at or near a target velocity. The robotic surgical instrument 700 can include a feedback controller, which can be one of any feedback controllers, including, but not limited to a PID, a state feedback, a linear-quadratic (LQR), and/or an adaptive controller, for example. The robotic surgical instrument 700 can include a power source to convert the signal from the feedback controller into a physical input such as case voltage, PWM voltage, frequency modulated voltage, current, torque, and/or force, for example. Additional details are disclosed in U.S. patent application Ser. No. 15/636,829, titled CLOSED LOOP VELOCITY CONTROL TECHNIQUES FOR ROBOTIC SURGICAL INSTRUMENT, filed Jun. 29, 2017, which is herein incorporated by reference in its entirety.

FIG. 17 illustrates a schematic diagram of a surgical instrument 750 configured to control the distal translation of a displacement member according to one aspect of this disclosure. In one aspect, the surgical instrument 750 is programmed to control the distal translation of a displacement member such as the closure member 764. The surgical instrument 750 comprises an end effector 752 that may comprise a clamp arm 766, a closure member 764, and an ultrasonic blade 768 coupled to an ultrasonic transducer 769 driven by an ultrasonic generator 771.

The position, movement, displacement, and/or translation of a linear displacement member, such as the closure member 764, can be measured by an absolute positioning system, sensor arrangement, and position sensor 784. Because the closure member 764 is coupled to a longitudinally movable drive member, the position of the closure member 764 can be determined by measuring the position of the longitudinally movable drive member employing the position sensor 784. Accordingly, in the following description, the position, displacement, and/or translation of the closure member 764 can be achieved by the position sensor 784 as described herein. A control circuit 760 may be programmed to control the translation of the displacement member, such as the closure member 764. The control circuit 760, in some examples, may comprise one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the processor or processors to control the displacement member, e.g., the closure member 764, in the manner described. In one aspect, a timer/counter 781 provides an output signal, such as the elapsed time or a digital count, to the control circuit 760 to correlate the position of the closure member 764 as determined by the position sensor 784 with the output of the timer/counter 781 such that the control circuit 760 can determine the position of the closure member 764 at a specific time (t) relative to a starting position. The timer/counter 781 may be configured to measure elapsed time, count external events, or time external events.

The control circuit 760 may generate a motor set point signal 772. The motor set point signal 772 may be provided to a motor controller 758. The motor controller 758 may comprise one or more circuits configured to provide a motor drive signal 774 to the motor 754 to drive the motor 754 as described herein. In some examples, the motor 754 may be a brushed DC electric motor. For example, the velocity of the motor 754 may be proportional to the motor drive signal 774. In some examples, the motor 754 may be a brushless DC electric motor and the motor drive signal 774 may comprise a PWM signal provided to one or more stator windings of the motor 754. Also, in some examples, the motor controller 758 may be omitted, and the control circuit 760 may generate the motor drive signal 774 directly.

The motor 754 may receive power from an energy source 762. The energy source 762 may be or include a battery, a super capacitor, or any other suitable energy source. The motor 754 may be mechanically coupled to the closure member 764 via a transmission 756. The transmission 756 may include one or more gears or other linkage components to couple the motor 754 to the closure member 764. A position sensor 784 may sense a position of the closure member 764. The position sensor 784 may be or include any type of sensor that is capable of generating position data that indicate a position of the closure member 764. In some examples, the position sensor 784 may include an encoder configured to provide a series of pulses to the control circuit 760 as the closure member 764 translates distally and proximally. The control circuit 760 may track the pulses to determine the position of the closure member 764. Other suitable position sensors may be used, including, for example, a proximity sensor. Other types of position sensors may provide other signals indicating motion of the closure member 764. Also, in some examples, the position sensor 784 may be omitted. Where the motor 754 is a stepper motor, the control circuit 760 may track the position of the closure member 764 by aggregating the number and direction of steps that the motor 754 has been instructed to execute. The position sensor 784 may be located in the end effector 752 or at any other portion of the instrument.

The control circuit 760 may be in communication with one or more sensors 788. The sensors 788 may be positioned on the end effector 752 and adapted to operate with the surgical instrument 750 to measure the various derived parameters such as gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors 788 may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a pressure sensor, a force sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector 752. The sensors 788 may include one or more sensors.

The one or more sensors 788 may comprise a strain gauge, such as a micro-strain gauge, configured to measure the magnitude of the strain in the clamp arm 766 during a clamped condition. The strain gauge provides an electrical signal whose amplitude varies with the magnitude of the strain. The sensors 788 may comprise a pressure sensor configured to detect a pressure generated by the presence of compressed tissue between the clamp arm 766 and the ultrasonic blade 768. The sensors 788 may be configured to detect impedance of a tissue section located between the clamp arm 766 and the ultrasonic blade 768 that is indicative of the thickness and/or fullness of tissue located therebetween.

The sensors 788 may be is configured to measure forces exerted on the clamp arm 766 by a closure drive system. For example, one or more sensors 788 can be at an interaction point between a closure tube and the clamp arm 766 to detect the closure forces applied by a closure tube to the clamp arm 766. The forces exerted on the clamp arm 766 can be representative of the tissue compression experienced by the tissue section captured between the clamp arm 766 and the ultrasonic blade 768. The one or more sensors 788 can be positioned at various interaction points along the closure drive system to detect the closure forces applied to the clamp arm 766 by the closure drive system. The one or more sensors 788 may be sampled in real time during a clamping operation by a processor of the control circuit 760. The control circuit 760 receives real-time sample measurements to provide and analyze time-based information and assess, in real time, closure forces applied to the clamp arm 766.

A current sensor 786 can be employed to measure the current drawn by the motor 754. The force required to advance the closure member 764 corresponds to the current drawn by the motor 754. The force is converted to a digital signal and provided to the control circuit 760.

The control circuit 760 can be configured to simulate the response of the actual system of the instrument in the software of the controller. A displacement member can be actuated to move a closure member 764 in the end effector 752 at or near a target velocity. The surgical instrument 750 can include a feedback controller, which can be one of any feedback controllers, including, but not limited to a PID, a state feedback, LQR, and/or an adaptive controller, for example. The surgical instrument 750 can include a power source to convert the signal from the feedback controller into a physical input such as case voltage, PWM voltage, frequency modulated voltage, current, torque, and/or force, for example.

The actual drive system of the surgical instrument 750 is configured to drive the displacement member, cutting member, or closure member 764, by a brushed DC motor with gearbox and mechanical links to an articulation and/or knife system. Another example is the electric motor 754 that operates the displacement member and the articulation driver, for example, of an interchangeable shaft assembly. An outside influence is an unmeasured, unpredictable influence of things like tissue, surrounding bodies and friction on the physical system. Such outside influence can be referred to as drag which acts in opposition to the electric motor 754. The outside influence, such as drag, may cause the operation of the physical system to deviate from a desired operation of the physical system.

Various example aspects are directed to a surgical instrument 750 comprising an end effector 752 with motor-driven surgical sealing and cutting implements. For example, a motor 754 may drive a displacement member distally and proximally along a longitudinal axis of the end effector 752. The end effector 752 may comprise a pivotable clamp arm 766 and, when configured for use, an ultrasonic blade 768 positioned opposite the clamp arm 766. A clinician may grasp tissue between the clamp arm 766 and the ultrasonic blade 768, as described herein. When ready to use the instrument 750, the clinician may provide a firing signal, for example by depressing a trigger of the instrument 750. In response to the firing signal, the motor 754 may drive the displacement member distally along the longitudinal axis of the end effector 752 from a proximal stroke begin position to a stroke end position distal of the stroke begin position. As the displacement member translates distally, the closure member 764 with a cutting element positioned at a distal end, may cut the tissue between the ultrasonic blade 768 and the clamp arm 766.

In various examples, the surgical instrument 750 may comprise a control circuit 760 programmed to control the distal translation of the displacement member, such as the closure member 764, for example, based on one or more tissue conditions. The control circuit 760 may be programmed to sense tissue conditions, such as thickness, either directly or indirectly, as described herein. The control circuit 760 may be programmed to select a control program based on tissue conditions. A control program may describe the distal motion of the displacement member. Different control programs may be selected to better treat different tissue conditions. For example, when thicker tissue is present, the control circuit 760 may be programmed to translate the displacement member at a lower velocity and/or with lower power. When thinner tissue is present, the control circuit 760 may be programmed to translate the displacement member at a higher velocity and/or with higher power.

In some examples, the control circuit 760 may initially operate the motor 754 in an open loop configuration for a first open loop portion of a stroke of the displacement member. Based on a response of the instrument 750 during the open loop portion of the stroke, the control circuit 760 may select a firing control program. The response of the instrument may include, a translation distance of the displacement member during the open loop portion, a time elapsed during the open loop portion, energy provided to the motor 754 during the open loop portion, a sum of pulse widths of a motor drive signal, etc. After the open loop portion, the control circuit 760 may implement the selected firing control program for a second portion of the displacement member stroke. For example, during the closed loop portion of the stroke, the control circuit 760 may modulate the motor 754 based on translation data describing a position of the displacement member in a closed loop manner to translate the displacement member at a constant velocity. Additional details are disclosed in U.S. patent application Ser. No. 15/720,852, titled SYSTEM AND METHODS FOR CONTROLLING A DISPLAY OF A SURGICAL INSTRUMENT, filed Sep. 29, 2017, which is herein incorporated by reference in its entirety.

FIG. 18 illustrates a schematic diagram of a surgical instrument 750 configured to control the distal translation of a displacement member according to one aspect of this disclosure. In one aspect, the surgical instrument 750 is programmed to control the distal translation of a displacement member such as the closure member 764. The surgical instrument 750 comprises an end effector 752 that may comprise a clamp arm 766, a closure member 764, and an ultrasonic blade 768 coupled to an ultrasonic transducer 769 driven by an ultrasonic generator 771.

The position, movement, displacement, and/or translation of a linear displacement member, such as the closure member 764, can be measured by an absolute positioning system, sensor arrangement, and position sensor 784. Because the closure member 764 is coupled to a longitudinally movable drive member, the position of the closure member 764 can be determined by measuring the position of the longitudinally movable drive member employing the position sensor 784. Accordingly, in the following description, the position, displacement, and/or translation of the closure member 764 can be achieved by the position sensor 784 as described herein. A control circuit 760 may be programmed to control the translation of the displacement member, such as the closure member 764. The control circuit 760, in some examples, may comprise one or more microcontrollers, microprocessors, or other suitable processors for executing instructions that cause the processor or processors to control the displacement member, e.g., the closure member 764, in the manner described. In one aspect, a timer/counter 781 provides an output signal, such as the elapsed time or a digital count, to the control circuit 760 to correlate the position of the closure member 764 as determined by the position sensor 784 with the output of the timer/counter 781 such that the control circuit 760 can determine the position of the closure member 764 at a specific time (t) relative to a starting position. The timer/counter 781 may be configured to measure elapsed time, count external events, or time external events.

The control circuit 760 may generate a motor set point signal 772. The motor set point signal 772 may be provided to a motor controller 758. The motor controller 758 may comprise one or more circuits configured to provide a motor drive signal 774 to the motor 754 to drive the motor 754 as described herein. In some examples, the motor 754 may be a brushed DC electric motor. For example, the velocity of the motor 754 may be proportional to the motor drive signal 774. In some examples, the motor 754 may be a brushless DC electric motor and the motor drive signal 774 may comprise a PWM signal provided to one or more stator windings of the motor 754. Also, in some examples, the motor controller 758 may be omitted, and the control circuit 760 may generate the motor drive signal 774 directly.

The motor 754 may receive power from an energy source 762. The energy source 762 may be or include a battery, a super capacitor, or any other suitable energy source. The motor 754 may be mechanically coupled to the closure member 764 via a transmission 756. The transmission 756 may include one or more gears or other linkage components to couple the motor 754 to the closure member 764. A position sensor 784 may sense a position of the closure member 764. The position sensor 784 may be or include any type of sensor that is capable of generating position data that indicate a position of the closure member 764. In some examples, the position sensor 784 may include an encoder configured to provide a series of pulses to the control circuit 760 as the closure member 764 translates distally and proximally. The control circuit 760 may track the pulses to determine the position of the closure member 764. Other suitable position sensors may be used, including, for example, a proximity sensor. Other types of position sensors may provide other signals indicating motion of the closure member 764. Also, in some examples, the position sensor 784 may be omitted. Where the motor 754 is a stepper motor, the control circuit 760 may track the position of the closure member 764 by aggregating the number and direction of steps that the motor 754 has been instructed to execute. The position sensor 784 may be located in the end effector 752 or at any other portion of the instrument.

The control circuit 760 may be in communication with one or more sensors 788. The sensors 788 may be positioned on the end effector 752 and adapted to operate with the surgical instrument 750 to measure the various derived parameters such as gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors 788 may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a pressure sensor, a force sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector 752. The sensors 788 may include one or more sensors.

The one or more sensors 788 may comprise a strain gauge, such as a micro-strain gauge, configured to measure the magnitude of the strain in the clamp arm 766 during a clamped condition. The strain gauge provides an electrical signal whose amplitude varies with the magnitude of the strain. The sensors 788 may comprise a pressure sensor configured to detect a pressure generated by the presence of compressed tissue between the clamp arm 766 and the ultrasonic blade 768. The sensors 788 may be configured to detect impedance of a tissue section located between the clamp arm 766 and the ultrasonic blade 768 that is indicative of the thickness and/or fullness of tissue located therebetween.

The sensors 788 may be is configured to measure forces exerted on the clamp arm 766 by a closure drive system. For example, one or more sensors 788 can be at an interaction point between a closure tube and the clamp arm 766 to detect the closure forces applied by a closure tube to the clamp arm 766. The forces exerted on the clamp arm 766 can be representative of the tissue compression experienced by the tissue section captured between the clamp arm 766 and the ultrasonic blade 768. The one or more sensors 788 can be positioned at various interaction points along the closure drive system to detect the closure forces applied to the clamp arm 766 by the closure drive system. The one or more sensors 788 may be sampled in real time during a clamping operation by a processor of the control circuit 760. The control circuit 760 receives real-time sample measurements to provide and analyze time-based information and assess, in real time, closure forces applied to the clamp arm 766.

A current sensor 786 can be employed to measure the current drawn by the motor 754. The force required to advance the closure member 764 corresponds to the current drawn by the motor 754. The force is converted to a digital signal and provided to the control circuit 760.

The control circuit 760 can be configured to simulate the response of the actual system of the instrument in the software of the controller. A displacement member can be actuated to move a closure member 764 in the end effector 752 at or near a target velocity. The surgical instrument 750 can include a feedback controller, which can be one of any feedback controllers, including, but not limited to a PID, a state feedback, LQR, and/or an adaptive controller, for example. The surgical instrument 750 can include a power source to convert the signal from the feedback controller into a physical input such as case voltage, PWM voltage, frequency modulated voltage, current, torque, and/or force, for example.

The actual drive system of the surgical instrument 750 is configured to drive the displacement member, cutting member, or closure member 764, by a brushed DC motor with gearbox and mechanical links to an articulation and/or knife system. Another example is the electric motor 754 that operates the displacement member and the articulation driver, for example, of an interchangeable shaft assembly. An outside influence is an unmeasured, unpredictable influence of things like tissue, surrounding bodies and friction on the physical system. Such outside influence can be referred to as drag which acts in opposition to the electric motor 754. The outside influence, such as drag, may cause the operation of the physical system to deviate from a desired operation of the physical system.

Various example aspects are directed to a surgical instrument 750 comprising an end effector 752 with motor-driven surgical sealing and cutting implements. For example, a motor 754 may drive a displacement member distally and proximally along a longitudinal axis of the end effector 752. The end effector 752 may comprise a pivotable clamp arm 766 and, when configured for use, an ultrasonic blade 768 positioned opposite the clamp arm 766. A clinician may grasp tissue between the clamp arm 766 and the ultrasonic blade 768, as described herein. When ready to use the instrument 750, the clinician may provide a firing signal, for example by depressing a trigger of the instrument 750. In response to the firing signal, the motor 754 may drive the displacement member distally along the longitudinal axis of the end effector 752 from a proximal stroke begin position to a stroke end position distal of the stroke begin position. As the displacement member translates distally, the closure member 764 with a cutting element positioned at a distal end, may cut the tissue between the ultrasonic blade 768 and the clamp arm 766.

In various examples, the surgical instrument 750 may comprise a control circuit 760 programmed to control the distal translation of the displacement member, such as the closure member 764, for example, based on one or more tissue conditions. The control circuit 760 may be programmed to sense tissue conditions, such as thickness, either directly or indirectly, as described herein. The control circuit 760 may be programmed to select a control program based on tissue conditions. A control program may describe the distal motion of the displacement member. Different control programs may be selected to better treat different tissue conditions. For example, when thicker tissue is present, the control circuit 760 may be programmed to translate the displacement member at a lower velocity and/or with lower power. When thinner tissue is present, the control circuit 760 may be programmed to translate the displacement member at a higher velocity and/or with higher power.

In some examples, the control circuit 760 may initially operate the motor 754 in an open loop configuration for a first open loop portion of a stroke of the displacement member. Based on a response of the instrument 750 during the open loop portion of the stroke, the control circuit 760 may select a firing control program. The response of the instrument may include, a translation distance of the displacement member during the open loop portion, a time elapsed during the open loop portion, energy provided to the motor 754 during the open loop portion, a sum of pulse widths of a motor drive signal, etc. After the open loop portion, the control circuit 760 may implement the selected firing control program for a second portion of the displacement member stroke. For example, during the closed loop portion of the stroke, the control circuit 760 may modulate the motor 754 based on translation data describing a position of the displacement member in a closed loop manner to translate the displacement member at a constant velocity. Additional details are disclosed in U.S. patent application Ser. No. 15/720,852, titled SYSTEM AND METHODS FOR CONTROLLING A DISPLAY OF A SURGICAL INSTRUMENT, filed Sep. 29, 2017, which is herein incorporated by reference in its entirety.

FIG. 18 is a schematic diagram of a surgical instrument 790 configured to control various functions according to one aspect of this disclosure. In one aspect, the surgical instrument 790 is programmed to control distal translation of a displacement member such as the closure member 764. The surgical instrument 790 comprises an end effector 792 that may comprise a clamp arm 766, a closure member 764, and an ultrasonic blade 768 which may be interchanged with or work in conjunction with one or more RF electrodes 796 (shown in dashed line). The ultrasonic blade 768 is coupled to an ultrasonic transducer 769 driven by an ultrasonic generator 771.

In one aspect, sensors 788 may be implemented as a limit switch, electromechanical device, solid-state switches, Hall-effect devices, MR devices, GMR devices, magnetometers, among others. In other implementations, the sensors 638 may be solid-state switches that operate under the influence of light, such as optical sensors, IR sensors, ultraviolet sensors, among others. Still, the switches may be solid-state devices such as transistors (e.g., FET, junction FET, MOSFET, bipolar, and the like). In other implementations, the sensors 788 may include electrical conductorless switches, ultrasonic switches, accelerometers, and inertial sensors, among others.

In one aspect, the position sensor 784 may be implemented as an absolute positioning system comprising a magnetic rotary absolute positioning system implemented as an AS5055EQFT single-chip magnetic rotary position sensor available from Austria Microsystems, AG. The position sensor 784 may interface with the control circuit 760 to provide an absolute positioning system. The position may include multiple Hall-effect elements located above a magnet and coupled to a CORDIC processor, also known as the digit-by-digit method and Volder's algorithm, that is provided to implement a simple and efficient algorithm to calculate hyperbolic and trigonometric functions that require only addition, subtraction, bitshift, and table lookup operations.

In some examples, the position sensor 784 may be omitted. Where the motor 754 is a stepper motor, the control circuit 760 may track the position of the closure member 764 by aggregating the number and direction of steps that the motor has been instructed to execute. The position sensor 784 may be located in the end effector 792 or at any other portion of the instrument.

The control circuit 760 may be in communication with one or more sensors 788. The sensors 788 may be positioned on the end effector 792 and adapted to operate with the surgical instrument 790 to measure the various derived parameters such as gap distance versus time, tissue compression versus time, and anvil strain versus time. The sensors 788 may comprise a magnetic sensor, a magnetic field sensor, a strain gauge, a pressure sensor, a force sensor, an inductive sensor such as an eddy current sensor, a resistive sensor, a capacitive sensor, an optical sensor, and/or any other suitable sensor for measuring one or more parameters of the end effector 792. The sensors 788 may include one or more sensors.

An RF energy source 794 is coupled to the end effector 792 and is applied to the RF electrode 796 when the RF electrode 796 is provided in the end effector 792 in place of the ultrasonic blade 768 or to work in conjunction with the ultrasonic blade 768. For example, the ultrasonic blade is made of electrically conductive metal and may be employed as the return path for electrosurgical RF current. The control circuit 760 controls the delivery of the RF energy to the RF electrode 796.

Additional details are disclosed in U.S. patent application Ser. No. 15/636,096, titled SURGICAL SYSTEM COUPLABLE WITH STAPLE CARTRIDGE AND RADIO FREQUENCY CARTRIDGE, AND METHOD OF USING SAME, filed Jun. 28, 2017, which is herein incorporated by reference in its entirety.

FIG. 19 illustrates an example of a generator 900, which is one form of a generator configured to couple to an ultrasonic instrument and further configured to execute adaptive ultrasonic blade control algorithms in a surgical data network comprising a modular communication hub. The generator 900 is configured to deliver multiple energy modalities to a surgical instrument. The generator 900 provides RF and ultrasonic signals for delivering energy to a surgical instrument either independently or simultaneously. The RF and ultrasonic signals may be provided alone or in combination and may be provided simultaneously. As noted above, at least one generator output can deliver multiple energy modalities (e.g., ultrasonic, bipolar or monopolar RF, irreversible and/or reversible electroporation, and/or microwave energy, among others) through a single port, and these signals can be delivered separately or simultaneously to the end effector to treat tissue. The generator 900 comprises a processor 902 coupled to a waveform generator 904. The processor 902 and waveform generator 904 are configured to generate a variety of signal waveforms based on information stored in a memory coupled to the processor 902, not shown for clarity of disclosure. The digital information associated with a waveform is provided to the waveform generator 904 which includes one or more DAC circuits to convert the digital input into an analog output. The analog output is fed to an amplifier 1106 for signal conditioning and amplification. The conditioned and amplified output of the amplifier 906 is coupled to a power transformer 908. The signals are coupled across the power transformer 908 to the secondary side, which is in the patient isolation side. A first signal of a first energy modality is provided to the surgical instrument between the terminals labeled ENERGY₁ and RETURN. A second signal of a second energy modality is coupled across a capacitor 910 and is provided to the surgical instrument between the terminals labeled ENERGY₂ and RETURN. It will be appreciated that more than two energy modalities may be output and thus the subscript “n” may be used to designate that up to n ENERGY_(n) terminals may be provided, where n is a positive integer greater than 1. It also will be appreciated that up to “n” return paths RETURN_(n) may be provided without departing from the scope of the present disclosure.

A first voltage sensing circuit 912 is coupled across the terminals labeled ENERGY₁ and the RETURN path to measure the output voltage therebetween. A second voltage sensing circuit 924 is coupled across the terminals labeled ENERGY₂ and the RETURN path to measure the output voltage therebetween. A current sensing circuit 914 is disposed in series with the RETURN leg of the secondary side of the power transformer 908 as shown to measure the output current for either energy modality. If different return paths are provided for each energy modality, then a separate current sensing circuit should be provided in each return leg. The outputs of the first and second voltage sensing circuits 912, 924 are provided to respective isolation transformers 916, 922 and the output of the current sensing circuit 914 is provided to another isolation transformer 918. The outputs of the isolation transformers 916, 928, 922 in the on the primary side of the power transformer 908 (non-patient isolated side) are provided to a one or more ADC circuit 926. The digitized output of the ADC circuit 926 is provided to the processor 902 for further processing and computation. The output voltages and output current feedback information can be employed to adjust the output voltage and current provided to the surgical instrument and to compute output impedance, among other parameters. Input/output communications between the processor 902 and patient isolated circuits is provided through an interface circuit 920. Sensors also may be in electrical communication with the processor 902 by way of the interface circuit 920.

In one aspect, the impedance may be determined by the processor 902 by dividing the output of either the first voltage sensing circuit 912 coupled across the terminals labeled ENERGY₁/RETURN or the second voltage sensing circuit 924 coupled across the terminals labeled ENERGY₂/RETURN by the output of the current sensing circuit 914 disposed in series with the RETURN leg of the secondary side of the power transformer 908. The outputs of the first and second voltage sensing circuits 912, 924 are provided to separate isolations transformers 916, 922 and the output of the current sensing circuit 914 is provided to another isolation transformer 916. The digitized voltage and current sensing measurements from the ADC circuit 926 are provided the processor 902 for computing impedance. As an example, the first energy modality ENERGY₁ may be ultrasonic energy and the second energy modality ENERGY₂ may be RF energy. Nevertheless, in addition to ultrasonic and bipolar or monopolar RF energy modalities, other energy modalities include irreversible and/or reversible electroporation and/or microwave energy, among others. Also, although the example illustrated in FIG. 19 shows a single return path RETURN may be provided for two or more energy modalities, in other aspects, multiple return paths RETURN_(n) may be provided for each energy modality ENERGY_(n). Thus, as described herein, the ultrasonic transducer impedance may be measured by dividing the output of the first voltage sensing circuit 912 by the current sensing circuit 914 and the tissue impedance may be measured by dividing the output of the second voltage sensing circuit 924 by the current sensing circuit 914.

As shown in FIG. 19, the generator 900 comprising at least one output port can include a power transformer 908 with a single output and with multiple taps to provide power in the form of one or more energy modalities, such as ultrasonic, bipolar or monopolar RF, irreversible and/or reversible electroporation, and/or microwave energy, among others, for example, to the end effector depending on the type of treatment of tissue being performed. For example, the generator 900 can deliver energy with higher voltage and lower current to drive an ultrasonic transducer, with lower voltage and higher current to drive RF electrodes for sealing tissue, or with a coagulation waveform for spot coagulation using either monopolar or bipolar RF electrosurgical electrodes. The output waveform from the generator 900 can be steered, switched, or filtered to provide the frequency to the end effector of the surgical instrument. The connection of an ultrasonic transducer to the generator 900 output would be preferably located between the output labeled ENERGY₁ and RETURN as shown in FIG. 18. In one example, a connection of RF bipolar electrodes to the generator 900 output would be preferably located between the output labeled ENERGY₂ and RETURN. In the case of monopolar output, the preferred connections would be active electrode (e.g., pencil or other probe) to the ENERGY₂ output and a suitable return pad connected to the RETURN output.

Additional details are disclosed in U.S. Patent Application Publication No. 2017/0086914, titled TECHNIQUES FOR OPERATING GENERATOR FOR DIGITALLY GENERATING ELECTRICAL SIGNAL WAVEFORMS AND SURGICAL INSTRUMENTS, which published on Mar. 30, 2017, which is herein incorporated by reference in its entirety.

As used throughout this description, the term “wireless” and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, although in some aspects they might not. The communication module may implement any of a number of wireless or wired communication standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 family), WMAX (IEEE 802.16 family), IEEE 802.20, long term evolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, Ethernet derivatives thereof, as well as any other wireless and wired protocols that are designated as 3G, 4G, 5G, and beyond. The computing module may include a plurality of communication modules. For instance, a first communication module may be dedicated to shorter range wireless communications such as Wi-Fi and Bluetooth and a second communication module may be dedicated to longer range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.

As used herein a processor or processing unit is an electronic circuit which performs operations on some external data source, usually memory or some other data stream. The term is used herein to refer to the central processor (central processing unit) in a system or computer systems (especially systems on a chip (SoCs)) that combine a number of specialized “processors.”

As used herein, a system on a chip or system on chip (SoC or SOC) is an integrated circuit (also known as an “IC” or “chip”) that integrates all components of a computer or other electronic systems. It may contain digital, analog, mixed-signal, and often radio-frequency functions—all on a single substrate. A SoC integrates a microcontroller (or microprocessor) with advanced peripherals like graphics processing unit (GPU), Wi-Fi module, or coprocessor. A SoC may or may not contain built-in memory.

As used herein, a microcontroller or controller is a system that integrates a microprocessor with peripheral circuits and memory. A microcontroller (or MCU for microcontroller unit) may be implemented as a small computer on a single integrated circuit. It may be similar to a SoC; an SoC may include a microcontroller as one of its components. A microcontroller may contain one or more core processing units (CPUs) along with memory and programmable input/output peripherals. Program memory in the form of Ferroelectric RAM, NOR flash or OTP ROM is also often included on chip, as well as a small amount of RAM. Microcontrollers may be employed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications consisting of various discrete chips.

As used herein, the term controller or microcontroller may be a stand-alone IC or chip device that interfaces with a peripheral device. This may be a link between two parts of a computer or a controller on an external device that manages the operation of (and connection with) that device.

Any of the processors or microcontrollers described herein, may be implemented by any single core or multicore processor such as those known under the trade name ARM Cortex by Texas Instruments. In one aspect, the processor may be an LM4F230H5QR ARM Cortex-M4F Processor Core, available from Texas Instruments, for example, comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2 KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, details of which are available for the product datasheet.

In one aspect, the processor may comprise a safety controller comprising two controller-based families such as TMS570 and RM4x known under the trade name Hercules ARM Cortex R4, also by Texas Instruments. The safety controller may be configured specifically for IEC 61508 and ISO 26262 safety critical applications, among others, to provide advanced integrated safety features while delivering scalable performance, connectivity, and memory options.

Modular devices include the modules (as described in connection with FIGS. 3 and 9, for example) that are receivable within a surgical hub and the surgical devices or instruments that can be connected to the various modules in order to connect or pair with the corresponding surgical hub. The modular devices include, for example, intelligent surgical instruments, medical imaging devices, suction/irrigation devices, smoke evacuators, energy generators, ventilators, insufflators, and displays. The modular devices described herein can be controlled by control algorithms. The control algorithms can be executed on the modular device itself, on the surgical hub to which the particular modular device is paired, or on both the modular device and the surgical hub (e.g., via a distributed computing architecture). In some exemplifications, the modular devices' control algorithms control the devices based on data sensed by the modular device itself (i.e., by sensors in, on, or connected to the modular device). This data can be related to the patient being operated on (e.g., tissue properties or insufflation pressure) or the modular device itself (e.g., the rate at which a knife is being advanced, motor current, or energy levels). For example, a control algorithm for a surgical stapling and cutting instrument can control the rate at which the instrument's motor drives its knife through tissue according to resistance encountered by the knife as it advances.

FIG. 20 is a simplified block diagram of one aspect of the generator 1100 for providing inductorless tuning as described above, among other benefits. With reference to FIG. 20, the generator 1100 may comprise a patient isolated stage 1520 in communication with a non-isolated stage 1540 via a power transformer 1560. A secondary winding 1580 of the power transformer 1560 is contained in the isolated stage 1520 and may comprise a tapped configuration (e.g., a center-tapped or non-center tapped configuration) to define drive signal outputs 1600 a, 1600 b, 1600 c for outputting drive signals to different surgical devices, such as, for example, an ultrasonic surgical device 1104 and an electrosurgical device 1106. In particular, drive signal outputs 1600 a, 1600 b, 1600 c may output a drive signal (e.g., a 420V RMS drive signal) to an ultrasonic surgical device 1104, and drive signal outputs 1600 a, 1600 b, 1600 c may output a drive signal (e.g., a 100V RMS drive signal) to an electrosurgical device 1106, with output 1600 b corresponding to the center tap of the power transformer 1560. The non-isolated stage 1540 may comprise a power amplifier 1620 having an output connected to a primary winding 1640 of the power transformer 1560. In certain aspects the power amplifier 1620 may comprise a push-pull amplifier, for example. The non-isolated stage 1540 may further comprise a programmable logic device 1660 for supplying a digital output to a digital-to-analog converter (DAC) 1680, which in turn supplies a corresponding analog signal to an input of the power amplifier 1620. In certain aspects the programmable logic device 1660 may comprise a field-programmable gate array (FPGA), for example. The programmable logic device 1660, by virtue of controlling the power amplifier's 1620 input via the DAC 1680, may therefore control any of a number of parameters (e.g., frequency, waveform shape, waveform amplitude) of drive signals appearing at the drive signal outputs 1600 a, 1600 b, 1600 c. In certain aspects and as discussed below, the programmable logic device 1660, in conjunction with a processor (e.g., processor 1740 discussed below), may implement a number of digital signal processing (DSP)-based and/or other control algorithms to control parameters of the drive signals output by the generator 1100.

Power may be supplied to a power rail of the power amplifier 1620 by a switch-mode regulator 1700. In certain aspects the switch-mode regulator 1700 may comprise an adjustable buck regulator, for example. As discussed above, the non-isolated stage 1540 may further comprise a processor 1740, which in one aspect may comprise a DSP processor such as an ADSP-21469 SHARC DSP, available from Analog Devices, Norwood, Mass., for example. In certain aspects the processor 1740 may control operation of the switch-mode power converter 1700 responsive to voltage feedback data received from the power amplifier 1620 by the processor 1740 via an analog-to-digital converter (ADC) 1760. In one aspect, for example, the processor 1740 may receive as input, via the ADC 1760, the waveform envelope of a signal (e.g., an RF signal) being amplified by the power amplifier 1620. The processor 1740 may then control the switch-mode regulator 1700 (e.g., via a pulse-width modulated (PWM) output) such that the rail voltage supplied to the power amplifier 1620 tracks the waveform envelope of the amplified signal. By dynamically modulating the rail voltage of the power amplifier 1620 based on the waveform envelope, the efficiency of the power amplifier 1620 may be significantly improved relative to a fixed rail voltage amplifier scheme. The processor 1740 may be configured for wired or wireless communication.

In certain aspects, the programmable logic device 1660, in conjunction with the processor 1740, may implement a direct digital synthesizer (DDS) control scheme to control the waveform shape, frequency and/or amplitude of drive signals output by the generator 1100. In one aspect, for example, the programmable logic device 1660 may implement a DDS control algorithm by recalling waveform samples stored in a dynamically-updated look-up table (LUT), such as a RAM LUT which may be embedded in an FPGA. This control algorithm is particularly useful for ultrasonic applications in which an ultrasonic transducer, such as the ultrasonic transducer 1120, may be driven by a clean sinusoidal current at its resonant frequency. Because other frequencies may excite parasitic resonances, minimizing or reducing the total distortion of the motional branch current may correspondingly minimize or reduce undesirable resonance effects. Because the waveform shape of a drive signal output by the generator 1100 is impacted by various sources of distortion present in the output drive circuit (e.g., the power transformer 1560, the power amplifier 1620), voltage and current feedback data based on the drive signal may be input into an algorithm, such as an error control algorithm implemented by the processor 1740, which compensates for distortion by suitably pre-distorting or modifying the waveform samples stored in the LUT on a dynamic, ongoing basis (e.g., in real-time). In one aspect, the amount or degree of pre-distortion applied to the LUT samples may be based on the error between a computed motional branch current and a desired current waveform shape, with the error being determined on a sample-by sample basis. In this way, the pre-distorted LUT samples, when processed through the drive circuit, may result in a motional branch drive signal having the desired waveform shape (e.g., sinusoidal) for optimally driving the ultrasonic transducer. In such aspects, the LUT waveform samples will therefore not represent the desired waveform shape of the drive signal, but rather the waveform shape that is required to ultimately produce the desired waveform shape of the motional branch drive signal when distortion effects are taken into account.

The non-isolated stage 1540 may further comprise an ADC 1780 and an ADC 1800 coupled to the output of the power transformer 1560 via respective isolation transformers 1820, 1840 for respectively sampling the voltage and current of drive signals output by the generator 1100. In certain aspects, the ADCs 1780, 1800 may be configured to sample at high speeds (e.g., 80 Msps) to enable oversampling of the drive signals. In one aspect, for example, the sampling speed of the ADCs 1780, 1800 may enable approximately 200× (depending on drive frequency) oversampling of the drive signals. In certain aspects, the sampling operations of the ADCs 1780, 1800 may be performed by a single ADC receiving input voltage and current signals via a two-way multiplexer. The use of high-speed sampling in aspects of the generator 1100 may enable, among other things, calculation of the complex current flowing through the motional branch (which may be used in certain aspects to implement DDS-based waveform shape control described above), accurate digital filtering of the sampled signals, and calculation of real power consumption with a high degree of precision. Voltage and current feedback data output by the ADCs 1780, 1800 may be received and processed (e.g., FIFO buffering, multiplexing) by the programmable logic device 1660 and stored in data memory for subsequent retrieval by, for example, the processor 1740. As noted above, voltage and current feedback data may be used as input to an algorithm for pre-distorting or modifying LUT waveform samples on a dynamic and ongoing basis. In certain aspects, this may require each stored voltage and current feedback data pair to be indexed based on, or otherwise associated with, a corresponding LUT sample that was output by the programmable logic device 1660 when the voltage and current feedback data pair was acquired. Synchronization of the LUT samples and the voltage and current feedback data in this manner contributes to the correct timing and stability of the pre-distortion algorithm.

In certain aspects, the voltage and current feedback data may be used to control the frequency and/or amplitude (e.g., current amplitude) of the drive signals. In one aspect, for example, voltage and current feedback data may be used to determine impedance phase, e.g., the phase difference between the voltage and current drive signals. The frequency of the drive signal may then be controlled to minimize or reduce the difference between the determined impedance phase and an impedance phase setpoint (e.g., 0°), thereby minimizing or reducing the effects of harmonic distortion and correspondingly enhancing impedance phase measurement accuracy. The determination of phase impedance and a frequency control signal may be implemented in the processor 1740, for example, with the frequency control signal being supplied as input to a DDS control algorithm implemented by the programmable logic device 1660.

The impedance phase may be determined through Fourier analysis. In one aspect, the phase difference between the generator voltage V_(g)(t) and generator current I_(g)(t) driving signals may be determined using the Fast Fourier Transform (FFT) or the Discrete Fourier Transform (DFT) as follows: V _(g)(t)=A ₁ cos(2πf ₀ t+φ ₁) I _(g)(t)=A ₂ cos(2πf ₀ t+φ ₂) V _(g)(f)=A ₁/2(δ(f−f ₀)+δ(f+f ₀))exp(j2πfφ ₁/2πf ₀) I _(g)(f)=A ₂/2(δ(f−f ₀)+δ(f+f ₀))exp(j2πfφ ₁/2πf ₀)

Evaluating the Fourier Transform at the frequency of the sinusoid yields: V _(g)(f ₀)=A ₁/2δ(0)exp(jφ ₁) arg V(f ₀)=φ₁ I _(g)(f ₀)=A ₂/2δ(0)exp(jφ ₂) arg I(f ₀)=φ₂

Other approaches include weighted least-squares estimation, Kalman filtering, and space-vector-based techniques. Virtually all of the processing in an FFT or DFT technique may be performed in the digital domain with the aid of the 2-channel high speed ADC 1780, 1800, for example. In one technique, the digital signal samples of the voltage and current signals are Fourier transformed with an FFT or a DFT. The phase angle φ at any point in time can be calculated by: φ=2πft+φ ₀

Where φ is the phase angle, f is the frequency, t is time, and φ₀ is the phase at t=0.

Another technique for determining the phase difference between the voltage V_(g)(t) and current I_(g)(t) signals is the zero-crossing method and produces highly accurate results. For voltage V_(g)(t) and current I_(g)(t) signals having the same frequency, each negative to positive zero-crossing of voltage signal V_(g)(t) triggers the start of a pulse, while each negative to positive zero-crossing of current signal I_(g)(t) triggers the end of the pulse. The result is a pulse train with a pulse width proportional to the phase angle between the voltage signal and the current signal. In one aspect, the pulse train may be passed through an averaging filter to yield a measure of the phase difference. Furthermore, if the positive to negative zero crossings also are used in a similar manner, and the results averaged, any effects of DC and harmonic components can be reduced. In one implementation, the analog voltage V_(g)(t) and current I_(g)(t) signals are converted to digital signals that are high if the analog signal is positive and low if the analog signal is negative. High accuracy phase estimates require sharp transitions between high and low. In one aspect, a Schmitt trigger along with an RC stabilization network may be employed to convert the analog signals into digital signals. In other aspects, an edge triggered RS flip-flop and ancillary circuitry may be employed. In yet another aspect, the zero-crossing technique may employ an eXclusive OR (XOR) gate.

Other techniques for determining the phase difference between the voltage and current signals include Lissajous figures and monitoring the image; methods such as the three-voltmeter method, the crossed-coil method, vector voltmeter and vector impedance methods; and using phase standard instruments, phase-locked loops, and other techniques as described in Phase Measurement, Peter O'Shea, 2000 CRC Press LLC, <http://www.engnetbase.com>, which is incorporated herein by reference.

In another aspect, for example, the current feedback data may be monitored in order to maintain the current amplitude of the drive signal at a current amplitude setpoint. The current amplitude setpoint may be specified directly or determined indirectly based on specified voltage amplitude and power setpoints. In certain aspects, control of the current amplitude may be implemented by control algorithm, such as, for example, a proportional-integral-derivative (PID) control algorithm, in the processor 1740. Variables controlled by the control algorithm to suitably control the current amplitude of the drive signal may include, for example, the scaling of the LUT waveform samples stored in the programmable logic device 1660 and/or the full-scale output voltage of the DAC 1680 (which supplies the input to the power amplifier 1620) via a DAC 1860.

The non-isolated stage 1540 may further comprise a processor 1900 for providing, among other things, user interface (UI) functionality. In one aspect, the processor 1900 may comprise an Atmel AT91 SAM9263 processor having an ARM 926EJ-S core, available from Atmel Corporation, San Jose, Calif., for example. Examples of UI functionality supported by the processor 1900 may include audible and visual user feedback, communication with peripheral devices (e.g., via a Universal Serial Bus (USB) interface), communication with a foot switch 1430, communication with an input device 2150 (e.g., a touch screen display) and communication with an output device 2140 (e.g., a speaker). The processor 1900 may communicate with the processor 1740 and the programmable logic device (e.g., via a serial peripheral interface (SPI) bus). Although the processor 1900 may primarily support UI functionality, it may also coordinate with the processor 1740 to implement hazard mitigation in certain aspects. For example, the processor 1900 may be programmed to monitor various aspects of user input and/or other inputs (e.g., touch screen inputs 2150, foot switch 1430 inputs, temperature sensor inputs 2160) and may disable the drive output of the generator 1100 when an erroneous condition is detected.

FIG. 21 illustrates a generator circuit 3500 partitioned into multiple stages where a first stage circuit 3504 is common to the second stage circuit 3506, in accordance with at least one aspect of the present disclosure. In one aspect, the surgical instruments of surgical system 1000 described herein may comprise generator circuit 3500 partitioned into multiple stages. For example, the surgical instruments of surgical system 1000 may comprise the generator circuit 3500 partitioned into at least two circuits: the first stage circuit 3504 and the second stage circuit 3506 of amplification enabling operation of high-frequency (RF) energy only, ultrasonic energy only, and/or a combination of RF energy and ultrasonic energy. A combination modular shaft assembly 3514 may be powered by a common first stage circuit 3504 located within the handle assembly 3512 and a modular second stage circuit 3506 integral to the modular shaft assembly 3514. As previously discussed throughout this description in connection with the surgical instruments of surgical system 1000, a battery assembly 3510 and the shaft assembly 3514 are configured to mechanically and electrically connect to the handle assembly 3512. The end effector assembly is configured to mechanically and electrically connect the shaft assembly 3514.

As shown in the example of FIG. 21, the battery assembly 3510 portion of the surgical instrument comprises a first control circuit 3502, which includes the control circuit 3200 previously described. The handle assembly 3512, which connects to the battery assembly 3510, comprises a common first stage drive circuit 3420. As previously discussed, the first stage drive circuit 3420 is configured to drive ultrasonic, high-frequency (RF) current, and sensor loads. The output of the common first stage drive circuit 3420 can drive any one of the second stage circuits 3506 such as the second stage ultrasonic drive circuit 3430, the second stage high-frequency (RF) current drive circuit 3432, and/or the second stage sensor drive circuit 3434. The common first stage drive circuit 3420 detects which second stage circuit 3506 is located in the shaft assembly 3514 when the shaft assembly 3514 is connected to the handle assembly 3512. Upon the shaft assembly 3514 being connected to the handle assembly 3512, the common first stage drive circuit 3420 determines which one of the second stage circuits 3506 (e.g., the second stage ultrasonic drive circuit 3430, the second stage RF drive circuit 3432, and/or the second stage sensor drive circuit 3434) is located in the shaft assembly 3514. The information is provided to the control circuit 3200 located in the handle assembly 3512 in order to supply a suitable digital waveform to the second stage circuit 3506 to drive the appropriate load, e.g., ultrasonic, RF, or sensor. It will be appreciated that identification circuits may be included in various assemblies 3516 in third stage circuit 3508 such as the ultrasonic transducer 1120, the electrodes 3074 a, 3074 b, or the sensors 3440. Thus, when a third stage circuit 3508 is connected to a second stage circuit 3506, the second stage circuit 3506 knows the type of load that is required based on the identification information.

FIG. 22 illustrates a diagram of a surgical system 4000, which represents one aspect of the surgical system 1000, comprising a feedback system for use with any one of the surgical instruments of surgical system 1000, which may include or implement many of the features described herein. The surgical system 4000 may include a generator 4002 coupled to a surgical instrument that includes an end effector 4006, which may be activated when a clinician operates a trigger 4010. In various aspects, the end effector 4006 may include an ultrasonic blade to deliver ultrasonic vibration to carry out surgical coagulation/cutting treatments on living tissue. In other aspects the end effector 4006 may include electrically conductive elements coupled to an electrosurgical high-frequency current energy source to carry out surgical coagulation or cauterization treatments on living tissue and either a mechanical knife with a sharp edge or an ultrasonic blade to carry out cutting treatments on living tissue. When the trigger 4010 is actuated, a force sensor 4012 may generate a signal indicating the amount of force being applied to the trigger 4010. In addition to, or instead of a force sensor 4012, the surgical instrument may include a position sensor 4013, which may generate a signal indicating the position of the trigger 4010 (e.g., how far the trigger has been depressed or otherwise actuated). In one aspect, the position sensor 4013 may be a sensor positioned with an outer tubular sheath or reciprocating tubular actuating member located within the outer tubular sheath of the surgical instrument. In one aspect, the sensor may be a Hall-effect sensor or any suitable transducer that varies its output voltage in response to a magnetic field. The Hall-effect sensor may be used for proximity switching, positioning, speed detection, and current sensing applications. In one aspect, the Hall-effect sensor operates as an analog transducer, directly returning a voltage. With a known magnetic field, its distance from the Hall plate can be determined.

A control circuit 4008 may receive the signals from the sensors 4012 and/or 4013. The control circuit 4008 may include any suitable analog or digital circuit components. The control circuit 4008 also may communicate with the generator 4002 and/or a transducer 4004 to modulate the power delivered to the end effector 4006 and/or the generator level or ultrasonic blade amplitude of the end effector 4006 based on the force applied to the trigger 4010 and/or the position of the trigger 4010 and/or the position of the outer tubular sheath described above relative to a reciprocating tubular actuating member located within an outer tubular sheath (e.g., as measured by a Hall-effect sensor and magnet combination). For example, as more force is applied to the trigger 4010, more power and/or higher ultrasonic blade amplitude may be delivered to the end effector 4006. According to various aspects, the force sensor 4012 may be replaced by a multi-position switch.

According to various aspects, the end effector 4006 may include a clamp or clamping mechanism. When the trigger 4010 is initially actuated, the clamping mechanism may close, clamping tissue between a clamp arm and the end effector 4006. As the force applied to the trigger increases (e.g., as sensed by force sensor 4012) the control circuit 4008 may increase the power delivered to the end effector 4006 by the transducer 4004 and/or the generator level or ultrasonic blade amplitude brought about in the end effector 4006. In one aspect, trigger position, as sensed by position sensor 4013 or clamp or clamp arm position, as sensed by position sensor 4013 (e.g., with a Hall-effect sensor), may be used by the control circuit 4008 to set the power and/or amplitude of the end effector 4006. For example, as the trigger is moved further towards a fully actuated position, or the clamp or clamp arm moves further towards the ultrasonic blade (or end effector 4006), the power and/or amplitude of the end effector 4006 may be increased.

According to various aspects, the surgical instrument of the surgical system 4000 also may include one or more feedback devices for indicating the amount of power delivered to the end effector 4006. For example, a speaker 4014 may emit a signal indicative of the end effector power. According to various aspects, the speaker 4014 may emit a series of pulse sounds, where the frequency of the sounds indicates power. In addition to, or instead of the speaker 4014, the surgical instrument may include a visual display 4016. The visual display 4016 may indicate end effector power according to any suitable method. For example, the visual display 4016 may include a series of LEDs, where end effector power is indicated by the number of illuminated LEDs. The speaker 4014 and/or visual display 4016 may be driven by the control circuit 4008. According to various aspects, the surgical instrument may include a ratcheting device connected to the trigger 4010. The ratcheting device may generate an audible sound as more force is applied to the trigger 4010, providing an indirect indication of end effector power. The surgical instrument may include other features that may enhance safety. For example, the control circuit 4008 may be configured to prevent power from being delivered to the end effector 4006 in excess of a predetermined threshold. Also, the control circuit 4008 may implement a delay between the time when a change in end effector power is indicated (e.g., by speaker 4014 or visual display 4016), and the time when the change in end effector power is delivered. In this way, a clinician may have ample warning that the level of ultrasonic power that is to be delivered to the end effector 4006 is about to change.

In one aspect, the ultrasonic or high-frequency current generators of the surgical system 1000 may be configured to generate the electrical signal waveform digitally such that the desired using a predetermined number of phase points stored in a lookup table to digitize the wave shape. The phase points may be stored in a table defined in a memory, a field programmable gate array (FPGA), or any suitable non-volatile memory.

Advanced Enemy Device Control Algorithms

Various control algorithms for ultrasonic surgical instruments and combination energy surgical instruments (e.g., ultrasonic/monopolar surgical instruments, monopolar/bipolar surgical instruments, ultrasonic/bipolar surgical instruments, and other such combination energy devices) are described herein. For the sake of clarity, surgical instruments will be referenced as surgical instrument 7012 in this section of the present disclosure, although the disclosure of this section could also apply to other surgical instruments referenced above such as surgical instrument 112, 700.

In various aspects, a control algorithm for a surgical instrument 7012 can be configured to achieve a constant heat flux along the length of the ultrasonic blade of surgical instrument 7012. The control algorithm can be applied by a control circuit and/or a surgical hub. The control circuit may execute a local computer executable program/algorithm of the surgical instrument 7012 or receive a suitable algorithm (e.g., impedance rate algorithm) from the surgical hub and/or the cloud computing system. Alternatively, the surgical hub could execute the algorithm remotely for the surgical instrument 7012. The constant heat flux may advantageously improve the quality of tissue coagulation, cutting, or sealing. The surgical instrument 7012 could be an ultrasonic and bipolar or a combination energy modality surgical instrument. The control algorithm may involve determining or adjusting clamp force in proportion to the progression of surgical coagulation of the tissue grasped by the surgical instrument 7012. Moreover, the control algorithm could involve variably changing, such as increasing, the clamp arm pressure applied on a tissue bite that has been loaded into the end effector, to produce constant heat flux along the blade length.

In particular, the power of electrosurgical energy delivered by the generator of surgical instrument 7012 as well as the applied clamp arm pressure can be adjusted or determine to attain a predefined heat flux. Additionally or alternatively, these can be adjusted to achieve a predefined amount of power to be applied to the tissue. For example, the control algorithm can comprise varying the RF and ultrasonic power level delivered by the generator in conjunction with varying the clamp arm pressure to achieve a predefined heat flux or power applied to the tissue. The heat flux could be constant or nearly constant over the weld time of the tissue relative to a surgical treatment cycle. The variation implemented by the control algorithm can be based on at least one parameter, which can include, for example, tissue impedance, blade natural frequency, temperature, or some other parameter (e.g., tissue operational parameter). Additionally or alternatively, the variation in clamp pressure and power level can be based on a heat flux controlled threshold. This heat flux controlled threshold can be dynamic so that the threshold adjusts along the blade length based on the progression of the surgical cutting and coagulation. This progression may be assessed by the corresponding focal point, which may be indicative of how well formed a fibrin clot is for coagulation, for example. Accordingly, a constant heat flux along the length of the blade could be generated, with the applied clamp force being proportional or corresponding to coagulation.

The control algorithm might also be configured to achieve constant heat flux by adjusting power over a series of sequential impedance set points based on the time to achieve a set point, in order to mimic impedance rise. In other words, as the generator of the surgical instrument 7012 progressively delivers power according to predetermined power curves (which define a relationship between power delivered to the tissue and the tissue impedance), the control circuit may be configured to determine whether the tissue impedance reaches a certain quantity at a certain time. When the certain quality is reached, the generator may be idle for a period of time and/or switch to a different power curve. If the certain quality is not reached, the generator may switch to a different power curve at that time or upon the control circuit determining that the certain quality will not or likely will not be reached. Additionally or alternatively, the control circuit could select power curves based on forecasting that applying the selected power curve would cause the tissue impedance to reach a particular impedance level at a particular time in the surgical treatment cycle.

The targeted or set tissue impedance points can be dependent on the next target point and/or the time required to reach the last set point. That is, for a series of tissue impedance points, each point can be determined based on its neighboring points, which may be either immediately before or after the subject point. Other points in the series can also be used to determine the value of the subject point. Each set point is defined as a tissue impendence target with an associated power level. For the series of impedance target points, as the delivery of power by the generator causes the tissue impedance to reach the subject point, the next tissue impedance target and power level can be determined. The subsequent impedance target point can be determined or adjusted based on overall tissue impedance level at that moment of the surgical treatment cycle and the time required to attain the previous impedance target point. The set points may include a predefined time, such as a dwell time, at the impedance target points prior to the control circuit determining the next adjustment.

In executing the control algorithm, the control circuit and/or surgical hub may cause the end effector of the surgical instrument 7012 to progressively close while applying a constant or nearly constant clamp force or pressure to the grasped tissue along the length of the ultrasonic blade. That is, the control circuit and/or surgical hub can adjust end effector closure to account for changes in clamp force applied to the tissue that result from the progression of the surgical coagulation and/or cutting treatment. For example, as grasped tissue is coagulated and cut at the proximal portion of the end effector, the corresponding proximal sections of the tissue may experience a greater applied clamp pressure due to the advancement of the surgical coagulation/cutting. Thus, as the control circuit and/or surgical hub senses or determines the progression of this coagulation/cutting action (e.g., via the sealing or weld focal point), it may adjust by increasing the clamp force applied to the distal sections of the tissue. In this way, each section of the grasped tissue may experience a uniform clamp pressure. As the location of the coagulation/cutting focal point shifts along the length of the end effector, the applied clamp force can be further adjusted. Additionally or alternatively, the clamp arm (alternatively referred to as the first jaw) of the end effector could be curved so as to accentuate or amplify the clamp force.

Because the curved clamp arm would result in different clamp pressure applied to tissue, the control algorithm may be executed to compensate for this clamp arm deflection. Thus, as the end effector gradually reaches its full closure stroke, the control circuit and/or surgical hub can execute the control algorithm to compensate for this deflection in order to provide a constant or near constant clamp tissue pressure along the length of the blade (alternatively referred to as the second jaw of the end effector). Accordingly, the end effector may apply relatively greater clamp force at the distal portions of the end effector when the tissue is being treated in a proximal to distal direction. Moreover, the clamp arm deflection may cause variation in heat flux along the length of the end effector. To address this, the control algorithm may involve selectively energizing surgical treatment electrodes (e.g., RF electrodes in the end effector) to compensate or account for this variation. Specifically, the RF electrodes could be segmented into proximal and distal segments and the control circuit and/or surgical hub could control the generator to selectively energize the RF electrode segments as appropriate to obtain a uniform and constant or approximately uniform and constant heat flux.

The control circuit and/or surgical hub can be configured to execute the control algorithm to control the energization of the segmented surgical treatment electrodes. For example, the electrodes may comprise two pairs of RF electrodes on each jaw of the end effector. The control circuit can control the energization in conjunction with the progressive closure of the clamp arm/first jaw to achieve a constant current density along the end effector. Each of the two pairs of RF electrodes could be referred to as a proximal and distal set of electrodes, respectively, and can be energized as a set. The control circuit may control the generator to sequentially energize the proximal and distal set of electrodes so that an equal current density is generated or created in both the proximal and distal portions. In one aspect, the control circuit and/or surgical hub may energize the proximal set of electrodes while causing the end effector to compress the tissue at a first jaw pressure, which results in a predefined current density. When the measured tissue impedance (e.g., measured via a pressure, resistive, or other suitable sensor in the end effector) reaches or exceeds a predetermined threshold, the control circuit and/or surgical hub may energize the distal set of electrodes and de-energize or cease applying power to the proximal set of electrodes. Simultaneously or substantially simultaneously, the clamp force applied by the clamp arm/first jaw may be increased to recreate the predefined current density in the distal area where the distal set of electrodes are located. In this way, the two proximal and distal set of electrodes can be energized or powered sequentially. Moreover, this sequential energizing can occur in conjunction with variable application of clamp force. Additionally or alternatively, as the proximal set of electrodes delivers electrosurgical energy to treat the tissue, the distal set of electrodes may simultaneously receive power from the generator at a lower power level for pre-heating. That is, the distal portion of the end effector may be pre-heated while the proximal portion is used to treat tissue. Similarly, the proximal portion of the end effector may also be pre-heated.

The surgical instrument 7012 may have a tissue (e.g., blood vessel) sealing mode in which a specific tissue impedance change over time or rise rate and predictable coagulation time interval are targeted. During operation of the energy-based surgical instrument 7012, the tissue impedance may be selectively increased in order to “starve” the coagulation cycle. Put differently, by applying electrosurgical energy according to target tissue impedance points and dwell time, the progression of the coagulation cycle can be dynamically halted or “starved” as necessary to achieve the desired impedance rate of change and coagulation time interval. In this way, the generator can adjust power by incrementing or cycling through different load or power curves based on target impedance set points with associated power levels and dwell times in between switching power levels or curves in order to obtain an overall coagulation time interval. The overall coagulation time may include changes in impedance rise rates, as discussed in more detail below. In one aspect, an impedance rise rate such as 50 Ohms (Ω) per second can be achieved adjusting the dwell time at each target to a target time interval such as 2 seconds (e.g., if applying the current power level or curve would otherwise increase the impedance to 100Ω) or increasing the number of targets and spacing them at specified increments such as 50Ω increments such that each power level or curve is applied until the next 50Ω target is reached.

Furthermore, selectively achieving tissue impedance rise rates can be performed to attain a predictable sealing time as measured by a surgical coagulation cycle. For example, the generator may apply power to the tissue according to a first power curve (e.g., specifying max power of 200 watts) to reach the target of 100Ω with a four second dwell time interval. After reaching 100Ω and dwelling for 4 seconds, the generator may achieve applying a series of power levels or curves. Each power level or curve can be determined and applied until reaching a next target impedance point with an associated power level and a dwell time, in which the target impedance points progressively increase by 100Ω (i.e., each point is 100Ω greater than the last). By controlling the generator in this manner, at each subject target impedance point, the applied power level or curve can be changed according to the next target impedance point. The next impedance point can have an associated power level and dwell time before the next impedance point is determined, which can be based on the overall tissue impedance level and time required to achieve the subject target impedance point. In adjusting impedance rise rates according to these dynamically determined target impedance points, a predictable sealing time could be achieved, such as a cycle time of 7 seconds in the example currently being described.

The surgical instrument 7012 may be configured to deliver a composite electrosurgical energy comprising ultrasonic and RF energy to separate treated tissue from a relatively hard or rigid substructure such as the patient's bone. To determine when this particular combination of electrosurgical energy should be applied, the sensors 788 can determine and monitor the natural or resonant frequency of the waveguide (and the blade that the waveguide terminates at). The waveguide natural frequency may be equivalent to the adjustment of the drive frequency made by the generator. In particular, the sensors 788 can detect when the natural frequency experiences a wave or phase shift in order to determine when the end effector may impact a hard substructure (e.g., bone, relatively harder layer of soft tissue, etc.). When such impact or contact is determined, the generator may be controlled to throttle back both the ultrasonic blade amplitude and RF power level. That is, the generator can reduce the transducer current used to vibrate the ultrasonic blade and the power transmitted to the RF electrodes.

Accordingly, the surgical instrument 7012 can properly separate tissue from a harder substructure using ultrasonic energy to complement the heat generated by the application of RF energy when the control circuit and/or surgical hub detects bone or differences in soft tissues based on the ultrasonic resonant frequency. The control algorithm could also be configured to detect and throttle back the application of electrosurgical energy upon detection of contact with non-tissue objects such as when underlying clips, staples are encountered or when the surgical instrument 7012 contacts another instrument.

As stated above, the surgical instrument 7012 could be a combination surgical instrument such as a combination monopolar/bipolar electrosurgical instrument in which the type of electrosurgical energy could be ultrasonic, RF, or some other suitable energy modality. In the monopolar modality, the patient being treated acts as the return path or electrical ground (e.g., via return pad on patient's skin) while in the bipolar modality, the ultrasonic blade acts as the second pole for the transmission of the electrosurgical energy. The bipolar modality may generally be preferred for more controlled, localized applications of electrosurgical energy. In this context, the control circuit and/or surgical hub can execute the control algorithm to alter the frequency of the electrosurgical monopolar energy so that it is non-therapeutic (outside treatment range) in order to monitor aspects of the bipolar modality or system. Thus, in aspects in which the surgical instrument 7012 functions as a bipolar tool such as surgical shears, the performance of the control algorithm can provide improved nerve sensing. Specifically, the bipolar and monopolar energy modalities could be applied simultaneously or nearly simultaneously with monopolar energy delivered to the end effector at a non-therapeutic frequency as feedback to the bipolar energy delivery. For example, the generator may deliver a drive signal for nerve stimulation such as a biphasic signal at 100-1000 hertz (Hz) to stimulate the patient's nerves in which the monopolar energy circuit provides monopolar energy at a non-therapeutic frequency while the bipolar energy circuit provides bipolar energy at a range of 200 kilohertz (kHZ) to 3 megahertz (MHz). In this way, the non-therapeutic monopolar component can be used as feedback to the control circuit and/or surgical hub to determine the end effector's proximity to the patient's nerves. Using the determined nerve proximity, the surgical instrument may minimize inadvertent cutting of nerves by the bipolar shears. Alternatively, the delivered bipolar energy could be feedback to the monopolar energy.

Furthermore, the surgical instrument 7012 might regulate the application of bipolar electrosurgical energy based on the change of impedance resulting from the application of monopolar electrosurgical energy. Specifically, the control circuit and/or surgical hub can perform the control algorithm to monitor the relative change of impedance from monopolar energy such that the control settings of the bipolar energy are controlled. The sensors 788, control circuit and/or surgical hub can detect or determine impedance based on a signal transmitted via the monopolar energy circuit. For example, the impedance could be determined by dividing the output of the monopolar voltage sensing circuit by the monopolar current sensing circuit. The bipolar control settings could be settings that define how the bipolar energy is delivered to the end effector. Thus, executing the control algorithm can result in controlling bipolar power using monitored monopolar impedance such as regulating bipolar power level based on changes in the determined monopolar impedance. For example, given an applied clamp arm pressure of 14-17 pounds tip load, the generator can cycle from zero power to full power mode such as 200 watts (W) and use the monopolar to measure the relative impedance increase (e.g., to a particular threshold, such as 80Ω) to control when to shift to a time-based control setting. That is, at the transition from 0 to 200 W, the determined change of 80Ω may be used to trigger a change to the time-based bipolar power control setting that specifies applying a constant amount of power such as 100 W for a predetermined amount of time. Alternatively, the determined change of 80Ω could cause a proportional step power decrease, such as a decrease in full power that is proportional to the increase in monopolar impedance.

The surgical instrument 7012 could also be a combination surgical instrument such as a combination monopolar/ultrasonic electrosurgical instrument in which the monopolar energy is used to sense or monitor surgical treatment using the ultrasonic modality. In particular, the operational frequency of the monopolar energy may be changed in order to monitor aspects of the ultrasonic energy modality. For example, the monopolar energy could initially be output at a therapeutic frequency level and switched to a lower, non-therapeutic frequency and power level to obtain tissue impedance measurements, which can be used for monitoring the ultrasonic energy delivery. Although absolute values of impedance may not be useful, changes in tissue impedance values can be compared against the expected changes in tissue impedance resulting from electrosurgical treatment in order to detect the tissue treatment effects of the delivered ultrasonic energy. In other words, as the tissue is being treated by the ultrasonic energy, there may be an expected change in tissue impedance. The control circuit and/or surgical hub may be configured to determine whether the tissue effects caused by the ultrasonic treatment are consistent with the expected change by using the change in frequency of the monopolar energy, such as by switching to a non-therapeutic frequency level.

The change in operation frequency of the monopolar energy modality for monitoring the ultrasonic energy modality could also be achieved by switching the drive frequency to a very high level, such as greater than 10 MHz to enable tissue monitoring. In this way, the change in monopolar frequency could be used to monitor the therapeutic effect on the tissue resulting from the other energy modality such as the ultrasonic energy modality, as discussed above. In some situations, undesirable parasitic impedances may result. However, the higher drive frequencies of the monopolar energy modality may beneficially negate or minimize parasitic or stray capacitance deriving from the use of a monopolar return pad (e.g., MEGADYNE™ MEGA SOFT™ Reusable Patient Return Electrode). Nonetheless, relatively higher therapeutic monopolar frequencies may also operate effectively even with the monopolar power set to lower levels to detect tissue impedances. As stated above, alternatively, the generator could drive the monopolar output at lower frequencies and sub-therapeutic currents for sensing ultrasonic treatment and the associated effects on treated tissue. Lower frequencies may not result in as many parasitic effects because of cable draping, lengths and other such reasons, but the sensing or monitoring of the ultrasonic energy modality may be limited by the usage of the monopolar return pad.

Although at least some portion of the control algorithm(s) disclosed herein can be performed by surgical hubs (alone or in conjunction with associated control circuits of surgical instruments), the functions of the control algorithm(s) are described as performed by control circuits for the sake of clarity. Also for clarity, the control circuit of surgical instrument 7012 in this portion of the present disclosure is labeled control circuit 710, although control circuit 710 can be the same or similar to control circuits 760, 3200, 3502, 4008. Control circuit 710 may be a part of the generator 4002 itself (referred to as generator 4002 for clarity although generator 4002 can be the same or similar to generator 140, 145, 240, 721, 771, 900, 1100) or another part of the surgical instrument 7012 that is remote from the generator 4002. In various aspects, the surgical instrument 7012 (e.g, ultrasonic surgical instrument) as described in FIGS. 23A-23B, 24A-24B, 25A-25B, 26A-26E, 27A-27F, is configured to operate with situational awareness in a hub environment, such as the surgical hub 106 or 206 (FIGS. 1-11), for example, as depicted by the timeline 5200.

FIGS. 23A-23B are graphs 203500, 203520 including a graph 203500 of clamp force as a function of time and an associated graph 203520 indicating the shift in the location of coagulation and cutting along the length of the blade as a function of time, in accordance with at least one aspect of the present disclosure. As depicted in FIG. 23A-23B, increasing the clamp force as the coagulation/cutting location (e.g., coagulation/cut focal point) on the ultrasonic blade shifts may result in better coupling of the tissue to the ultrasonic blade. The focal point may shift from proximally to distally or distally to proximally depending on the direction of the surgical treatment, for example. Moreover, the focal point might represent the progress of a fibrin clot for coagulation, for example. The clamp arm of the surgical instrument 7012 could be offset, sloped, or otherwise curved to accentuate or amplify the pressure experienced by the tissue, which results from the application of clamp force. The focal point as well as a total sealing or welding time of the surgical operation could be determined by the control circuit 710 based on a sensor signal (e.g., from sensor 788) indicative of a surgical parameter such as tissue impedance, natural frequency, temperature, or some suitable tissue parameter. The control circuit 710 could increase the clamp arm pressure based on the sensor signal. The change in clamp force as a function of surgical coagulation/cutting location could be controlled by the control circuit 710 in conjunction with a variation in electrosurgical power level delivered by the generator in order to attain a predefined heat flux or power applied to the tissue.

The heat flux could be implemented by the control circuit 710 as a heat flux control threshold that may stay the same or change over the duration of the surgical operation performed by the surgical instrument 7012, such as based on the progression of the surgical cutting/coagulation. For example, the control circuit 710 could adjust the heat flux control threshold based on the determined coagulation focal point, progression of the focal point, and/or progression of the cutting. The predefined heat flux may beneficially improve the quality of surgical treatment, such as the tissue seal that is formed. In FIG. 23A, the x-axis 203508 denotes time such as the time over the course of a surgical cycle while y-axis 203510 denotes applied clamp force. As such, the time spanning time t₀ to time t₁₀ can define a surgical cycle of the surgical instrument 7012. Clamp force can be measured in suitable units such as pounds (lbs). As shown in graph 203500, the y-axis 203510 has annotations for a maximum and minimum clamp force level.

The dashed line 203502 represents the force applied by the clamp arm over time and tracks the application of force by the clamp arm, from the minimum force at time t₀ to maximum force at time t₁₀. The value or amount of the clamp force may be a function of the process of the tissue coagulation process, which could be tracked based on the location of the coagulation/cut focal point on the end effector as it spans t₀ to time t₁₀. As illustrated by dashed line 203502, the applied clamp force increases as tissue coagulation/cutting action is sensed. The dashed line 203502 reaches the maximum force at a point close to time t₆, where the force stays at its maximum level until time t₁₀. The dash-and-dot line 203504 represents the measured tissue impedance over the surgical cycle. As can be seen on graph 203500, the measured tissue impedance decreases from its initial level at time t₀ to the low point at around time t₃, demonstrating the drop in impedance resulting from the commencement of surgical treatment (the so-called “bathtub” portion of the impedance curve). After time t₃, the tissue impedance line 203504 rises as the tissue being treated begins to dry out. This desiccation results in an increase in tissue impedance. FIG. 23A shows how this increase in tissue impedance line 203504 corresponds to an increase in the applied clamp force line 203502. The increase in applied force may assist in cutting the tissue and welding the denatured tissue as the surgical cycle is completed. Also, the clamp arm could be curved to accentuate the tissue pressure resulting from increased clamp force. Additionally, the end effector may progressively close while providing a constant or almost constant tissue clamp pressure along the length of the end effector or ultrasonic blade. The constant or near constant clamp pressure is depicted by solid line 203506, which may correspond to the pressure applied at the leading edge of the end effector, where surgical coagulation and cutting occur. As such, the solid line 203506 stays at an approximately constant level, with minimal or no fluctuations.

FIG. 23B shows that the focal point of the surgical coagulation and cutting operation on the tissue shifts along the length of ultrasonic blade or second jaw 203524 (similar to or the same as ultrasonic blade 718, 768 or other ultrasonic blades described above) over the course of the surgical cycle. As shown in FIG. 23B, the focal point shifts in a proximal to distal direction over time, but the focal point could also shift in a distal to proximal direction. The progress of the tissue coagulation/cutting focal point over the surgical cycle can be represented by the black dots 203522A, 203522B, to 203522N, whose advance corresponds to the advance of time through the surgical cycle spanning time points t₀ to time t₁₀. That is, each one of the black dots 203522A, 203522B, to 203522N corresponds to a time point in the surgical cycle and also represents the formation of the tissue seal and/or progress of the tissue treatment. For example, the black dots could represent a coagulation focus or focal point determined by the control circuit 710 based on a signal from sensor 788. The sensor signal may be indicative of a surgical parameter such as tissue impedance, a natural frequency of the ultrasonic blade, temperature, or some other tissue parameter. Based on the sensor signal, the control circuit 710 may determine the progression of the tissue seal/weld/coagulation focal point and further determine a tissue weld/seal time for a surgical operation being performed by the surgical instrument 7012.

Moreover, the control circuit 710 may be configured to control the closure of the end effector while compensating for clamp arm deflection, which may result from the curved shape of the end effector. For example, the control circuit 710 could mechanically adjust the force applied by the clamp arm to offset any disproportionate force exerted based on the curvature of the clamp arm so that a constant or near constant tissue pressure is provided along the length of the end effector. Furthermore, the control circuit 710 may selectively energize different segments (e.g., proximal and distal) of RF electrodes such as RF electrodes 796 in order to compensate or adjust for heat flux variation caused by the clamp arm deflection, as described in more detail below. The control circuit 710 could be configured to determine the cut/weld focal point based on one or more of the resonant frequency and electrical continuity feedback measures. A constant heat flux along the length of the ultrasonic blade 203524 may also be achieved. For example, as tissue is coagulated and cut at the proximal sections of the end effector, the delivered electrosurgical power level is relatively higher at those proximal sections. Accordingly, the control circuit 710 might execute the control algorithm to increase the clamp force at the distal sections, which results in higher current density at the distal sections that may compensate for the relatively lower power level at the distal sections. In this way, the heat flux and pressure experienced by the tissue along the ultrasonic blade 203524 may be constant and/or consistent with the heat flux control threshold. The control circuit 710 may receive, from a sensor 788, a sensor signal indicative of a surgical parameter. The surgical parameter may be tissue impedance, a natural frequency of the ultrasonic blade, temperature, or a tissue parameter. The weld time of the surgical operation can be determined by the control circuit 710 based on the sensor signal. The control circuit 710 can vary one or more of a clamp arm pressure applied by the clamp arm and a power level of the electrosurgical energy to maintain one or more of a predefined heat flux or power applied to tissue loaded in the end effector.

FIGS. 24A-24B depict segments of end effector electrodes and an illustration of controlling applied clamp force and delivered electrosurgical energy by the end effector, in accordance with at least one aspect of the present disclosure. FIG. 24A shows the end effector 203540 in an open configuration. The end effector 203540 can be the same or similar to any suitable end effector described above, such as end effector 702, 752, 792, 4006, or some other appropriate end effector. As shown in FIG. 24A, the end effector 203540 comprises two jaws including first jaw (e.g., clamp arm) 203542 and second jaw/ultrasonic blade 203544 (same or similar as ultrasonic blade 203524). The clamp arm 203542 can be the same or similar to any suitable clamp arm described above, such as clamp arm 716, 766, or some other appropriate clamp arm. Each of the first and second jaws 203542, 203544 each comprise electrosurgical electrodes 203546A-203546D, 203548A-203548D, respectively. The electrosurgical electrodes 203546A-203546D, 203548A-203548D can be the same or similar to RF electrodes such as RF electrodes 796 or any other appropriate electrodes described above. The electrosurgical electrodes 203546A-203546D, 203548A-203548D may each be segmented into proximal and distal portions or segments. For example, the electrodes 203546A-203546B, 203548A-203548B may form a proximal electrode pair or segment on the first and second jaws 203542, 203544, respectively. Similarly, the electrodes 203546C-203546D, 203546C-203546D may form a distal electrode pair or segment on the first and second jaws 203542, 203544, respectively. In this way, the electrodes 203546A-203546B, 203548A-203548B could be segmented longitudinally. The longitudinally segmented electrodes may generate a constant current density.

The control circuit 710 may be configured to execute a control algorithm to control the application of power to the segmented electrodes 203546A-203546B, 203548A-203548B by the generator 4002 in conjunction with controlling the progressive closure of the clamp arm 203542 in order to obtain a constant or near constant current density throughout the end effector 203540. FIG. 24B illustrates an example of this. In FIG. 24B, the end effector 203560 applies different clamp pressure on the tissue 203570 based on the different clamp forces resulting from the different end effector closure angles θ₁, θ₂. In particular, the control circuit 710 may control the end effector 203560 to compress the tissue 203570 to a first jaw pressure (which could be predetermined or dynamically determined) while controlling the generator 4002 to energize the proximal set of electrodes 203546A-203546B, 203548A-203548B in order to create a first predefined current density. The generator 4002 could deliver power to one of the proximal electrode pair individually or to both pairs in conjunction. Moreover, the generator 4002 could power the end effector jaws individually such as by only applying power electrode pair 203546A-203546B on first jaw 203542, power them sequentially, or in conjunction. As such, the control circuit 710 may energize the electrode segments 203546A-203546D, 203548A-203548D based on a progressive closure stroke of the clamp arm 203542.

A tissue impedance signal (or signals indicative of current and voltage) may be output by sensor 788 (e.g., pressure, resistive, or other suitable sensor) and transmitted to the control circuit 10 as feedback. When the control circuit 710 determines that the tissue impedance has reached a predetermined or dynamically determined threshold, the control circuit 710 may control the end effector 203560 and generator 4002 to change one or more of clamp force and power level (e.g., to reach a constant heat flux and/or the heat flux control threshold). In particular, the end effector 203560 may be controlled to apply an increased jaw pressure that is higher than the first jaw pressure. Simultaneously or in the same time frame, the control circuit 710 controls the generator 4002 to power off the proximal electrode pair and instead deliver power to one of the distal electrode pair individually or to both pairs in conjunction. That is, the generator 4002 powers one or more of the distal segment of electrodes 203546C-203546D, 203546C-203546D. In this way, the same current density in the clamped tissue may be obtained for the distal electrodes or portion of the end effector 203560 as the proximal electrodes or portion of the end effector 203560. The current density could be predetermined or dynamically determined, as appropriate. As depicted in FIGS. 24A-24B, increasing the clamp load pressure on the tissue 203570 corresponds to an increase in the angle between the clamp arm/first jaw 203562 and the ultrasonic blade/second jaw 203564 to decrease from θ₁ to θ₂. Also as shown in FIGS. 24A-24B, the first and second jaw 203562, 203564 pivot about pivot point 203568 to implement the end effector closure stroke.

FIGS. 25A-25B are graphs 203580, 203600 illustrating controlling the energization or powering of the electrosurgical electrodes 203546A-203546D, 203548A-203548D, in accordance with at least one aspect of the present disclosure. As discussed above, the control circuit 710 may be configured to execute the control algorithm to control the end effector 203560 and generator 4002 to produce or generate a constant current density. During treatment of the proximal portion of the end effector 203560, the control circuit 710 may control the end effector to compress the tissue 203570 in the proximal portion to a first clamp pressure. Simultaneously or in the same time frame, the generator 4002 may deliver power to only the proximal electrode pairs 203546A-203546B, 203548A-203548B to surgically treat the proximal section. Either or both of the electrodes in the first and second jaws 203562, 203564 could be energized such that one or both of the proximal first electrode pair 203546A-203546B and proximal second electrode pair 203548A-203548B could be energized. After surgical treatment of the proximal portion, the generator 4002 may deliver power to the distal electrodes 203546C-203546D, 203548C-203548D to treat the distal portion of the end effector 203560. Either or both of the electrodes in the first and second jaws 203562, 203564 could be energized such that one or both of the distal first electrode pair 203546A-203546B and distal second electrode pair 203548A-203548B could be energized. In this way, the electrosurgical electrodes 203546A-203546D, 203548A-203548D may be sequentially energized by the generator 4002.

FIG. 25A illustrates delivering power to the proximal (referenced as electrode pair “a”) and then distal (referenced as electrode pair “b”) electrodes sequentially as the clamp pressure experienced by the tissue 203570 is increased in a corresponding manner. The x-axis 203582 of graph 203580 denotes time, such as in units of seconds, which could span the length of a surgical cycle. The y-axes 203584, 203585 respectively denote power level, such as expressed as a percentage of maximum power (100%), and clamp pressure experienced by the tissue 203570 (e.g., measured in pounds). The graph 203580 depicts the sequence of proximal electrode pairs “a” 203546A-203546B, 203548A-203548B being activated and treating tissue for a first period of time indicated on the x-axis 203582 followed by distal electrode pairs “b” 203546C-203546D, 203548C-203548D being activated and treating tissue for a second period of time indicated on the x-axis. The rectangular function of graph 203580 illustrates this sequential energization. The generator 4002 first powers electrode pairs “a” 203546A-203546B, 203548A-203548B according to power level line 203586, deactivates “a,” then powers electrode pairs “b” 203546C-203546D, 203548C-203548D according to power level line 203588, and finally deactivates “b.” Simultaneously or in the same time frame, the control circuit 710 may be controlling the end effector 203560 to apply clamp pressure at level P₁ while electrode pairs “a” are activated and apply clamp pressure at level P₂ while electrode pairs “b” are activated. This application of clamp pressure is represented by clamp pressure line 203590. Upon completion of surgical treatment of the proximal and distal portions, the generator 4002 ceases delivering power and the end effector 203560 returns to the open configuration.

FIG. 25B illustrates pre-heating the distal electrode pairs “b” 203546C-203546D, 203548C-203548D. Accordingly, while the proximal portion of the end effector 203560 is being treated, the control circuit 710 may also control the generator 4002 to pre-heat the distal portion. In other words, during the time spanning the activation of electrode pairs “a” 203546A-203546B, 203548A-203548B, the generator 4002 may deliver power to the distal electrode pairs “b” 203546C-203546D, 203548C-203548D at a lower power level to facilitate surgical treatment in the distal portion after completion of surgical treatment in the proximal portion. Graph 203600 depicts this. The x-axis 203602 of graph 203600 denotes time, such as in units of seconds, which could span the length of a surgical cycle. The y-axes 203604, 203605 respectively denote power level, such as expressed as a percentage of maximum power (100%), and clamp pressure experienced by the tissue 203570 (e.g., measured in pounds). The power level line 203606 of graph 203600 shows the sequential activation of electrode pairs “a” similarly to power level line 203586. The power level line 203608 shows a similar activation of electrode pairs “b” except that the generator 4002 may deliver power to the distal electrode pairs “b” 203546C-203546D, 203548C-203548D at a lower power level, e.g., 20% of the maximum power level (100%) applied at the peak of the rectangular function. This applied lower power level enables the distal portion of the end effector 203560 to be pre-heated prior to treatment. Simultaneously or in the same time frame, the control circuit 710 controls the end effector 203560 to apply clamp pressure at level P₁ and level P₂ as represented by clamp pressure line 203610. Also, the control circuit 710 could control the generator 4002 in an opposite manner so that the proximal portion of the end effector 203560 is pre-heated prior to treatment.

FIGS. 26A-26E are a series of graphs 203620, 203640, 203660, 203680, 203700 illustrating the adjustment of power level to achieve a predictable sealing time, in accordance with at least one aspect of the present disclosure. The x-axis 203622, 203642, 203662, 203682, 203702 denotes tissue impedance which can be measured in units of Ohms (Ω). The y-axis 203624, 203644, 203664, 203684, 203704 denotes the power level applied by the generator 4002. The graphs 203620, 203640, 203660, 203680, 203700 demonstrate how a series of sequential impedance points may be set to mimic an impedance rise corresponding to a particular tissue coagulation time. By attaining a target impedance rise rate and predictable coagulation time interval for the surgical instrument (e.g., in vessel sealing mode), a more secure or otherwise better tissue seal may be achieved. Each impedance point in the sequential series may be set based on the next target power level and/or impedance as well as the time in the surgical cycle required for reaching the immediately preceding or other previously set impedance points. Upon reaching a specific impedance point, the control circuit 710 may determine the next set impedance point and associated power level in order to achieve and/or maintain a desired rise in tissue impedance. In particular, the control circuit 710 might be configured to control the rise in tissue impedance so that the impedance of tissue 203570 changes according to an impedance versus time curve (“bathtub curve”) that resembles the shape of a “bathtub.” The impedance versus time curve may be characterized by an initial drop in tissue impedance upon initial application of electrosurgical energy until stabilizing (minimum point), which is followed by a rise in tissue impedance corresponding to the desiccation of the tissue 203570. The overall or contemporaneous tissue impedance level relative to this impedance bathtub curve, as assessed by the sensor 788 and control circuit 710, might also be used to adjust the next set impedance point.

The power level associated with each impedance point may be determined based on a power level that achieves a subsequent impedance point which tracks a different impedance versus time curve compared to the default impedance bathtub curve. The different impedance curve may be less (although it could be more as well) aggressive than the bathtub curve, for example. In this way, as each impedance point in the series is achieved and each associated power level is determined according to the desired impedance versus time curve, a desired rise in impedance may be mimicked. This rise in impedance may correspond to the drying out of the tissue 203570, except that the rise may be adjusted relative to the default bathtub curve so that an improved tissue seal may be obtained. Additionally or alternatively, by dynamically determining the set impedance points and associated power levels, the control circuit 710 may implement the surgical treatment according to a predictable coagulation time interval. The associated power level determined for each set impedance point may be one or more power values. In particular, the associated power level may be determined according to a load or power curve. The power curve could be a predetermined power curve stored in the memory of the surgical instrument 7012, a dynamically determined power curve according to a mathematical model or equation (e.g., a change in the variables used in the equation to determine power or a different equation altogether), or some other suitable means, for example.

Accordingly, the impedance points could be dynamically determined or targeted to achieve a selective impedance increase. As discussed above, by controlling the rate of rise of impedance of the tissue 203570 in this way, the tissue coagulation may be more predictable and improved. Also, there could be a dwell time between adjacent impedance set points in the series. This dwell time between impedance points may “starve” the coagulation cycle. That is, during the dwell time, the generator 4002 may not deliver any power to the end effector 203560 such that the impedance of the tissue 203570 does not change significantly during the dwell time. The graph 203620 may show a natural load or power curve (e.g., curve representing power level as a function of tissue impedance) as indicated by the plotted applied power line 203626. The applied power line 203620 also shows the dwell time. The natural power curve could be the desired impedance versus time curve including a desired rise in impedance that is achieved dynamically as impedance points in the series are set. In particular, the graph 203640 portrays the first set impedance point in the series of sequential impedance points.

The first set point occurs at 100Ω such that the generator 4002 delivers the associated power level rising up to maximum power such as 200 Watts (W) to achieve 100Ω. The associated power level(s) could be determined based on: applying a power curve stored in memory of the surgical instrument 7012, corresponding surgical hub and/or cloud; applying a segment or particular portion of a power curve; or determining an appropriate level such as by reference to the desired natural power curve. As can be seen in graph 203640, the corresponding first power curve is applied as represented by applied power line 203646 to incrementally mimic the natural power curve. The applied power line 203646 also shows the dwell time. As such, the desired rise rate and natural power curve could be used as a guide in conjunction with the elapsed time for determining the next impedance point and associated power level. The remainder of the first power curve or power level(s) is generally represented by the dotted line 203648. Upon reaching the first set impedance point at 100Ω, the generator 4002 may dwell for a suitable period of time. This dwell time could be predefined or contemporaneously determined by the control circuit 710 and may be useful for temporarily pausing or slowing the coagulation cycle. During the dwell time, the control circuit 710 may assess the progress of the tissue coagulation, which might be compared to the desired natural power curve, for example. The dwell time might be four seconds, for example. After dwelling for four seconds, the control circuit 710 may determine that the next set impedance point is 200Ω based on various factors such as reference to the last set point of 100Ω, an estimated next impedance point, and/or the desired natural power curve (e.g., the overall or contemporaneous impedance level of the tissue 203570 relative to the natural power curve).

Also, the control circuit 710 may determine that the corresponding power level is lower than 200 W, such as according to a second power curve that gradually reduces the power level to below 200 W. This second power curve or power level(s) might be different from the first power curve or power level(s). Similar to the first set impedance point, the generator 4002 may deliver power to mimic or follow a desired impedance rise rate and/or in accordance with the natural power curve. That is, the generator 4002 may deliver power so that the second set impedance point is anticipated to be reached in a desired amount of time. The graph 203660 includes applied power line 203666, which shows the application of this second associated power by the generator 4002 to reach 200Ω and the dwell time. The remainder of the second power curve or power level(s) is generally represented by the dotted line 203668. Upon the impedance reaching 200Ω, the control circuit 710 may determine the amount of dwell time that is appropriate. For example, the control circuit 710 might determine that the generator 4002 should dwell for 1 second to pause the tissue coagulation. The control circuit 710 can further determine the next target impedance point is set at 300Ω as the impedance reaches 200Ω. As discussed above, the 300Ω can be determined based on factors such as reference to the last set point of 200Ω, an estimated next impedance point, and/or the desired natural power curve. The associated third power curve or power level(s) to be applied by the generator 4002 can be determined by reference to or in accordance with a desired impedance rise rate and/or natural power curve, as described above. The third power curve or power level(s) could be used to change the relative rate of change of power level as a function of impedance as shown in graph 203680. The remainder of the third power curve or power level(s) is generally represented by the dotted line 203688.

After dwelling for 1 second, the generator 4002 may deliver power according to the corresponding third power curve or power level(s) until reaching the next set impedance point of 300Ω. This is illustrated by graph 203680. In graph 203680, the applied power line 203686 represents delivering power according to the third power curve or power level(s) and the determined dwell time. Similarly to as described above, the control circuit 710 may implement a predetermined or contemporaneously determine dwell time upon reaching 300Ω. Moreover, the control circuit 710 may determine the next impedance point to be set is 400Ω based on the various factors described above. Additionally, the control circuit 710 may change/determine the corresponding power level is a fourth power curve or power level(s). The generator 4002 can deliver power according to this fourth power curve or power level(s), as represented by applied power line 203706, until reaching the next impedance set point. The remainder of the second power curve or power level(s) is generally represented by the dotted line 203708. As the tissue impedance reached the 300Ω set point, the control circuit 710 could determine the next set point is 400Ω, similarly to the determination of previous impedance points in the series. Upon reaching the 400Ω, the control circuit 710 may determine that the tissue coagulation is complete and therefore terminate the coagulation process. This is illustrated by graph 203700. More or less set impedance points could be used, as appropriate. Based on using these dynamically determined series of set impedance points and associated power, the control circuit 710 may mimic a desired impedance rise so as to obtain a predictable coagulation time interval. The impedance points and dwell time can be used to assist in determining an “impromptu” or contemporaneously determined power curve. In other words, the generator 4002 can apply segments or portions of different power curves and/or power level(s) as appropriate. Although FIGS. 26A-26E depict the use of dwell time, in other aspects, dwell time might not be used. In the surgical cycle portrayed in FIGS. 26A-26E, a total dwell time of 7 seconds may be realized during the surgical cycle with a difference of 100Ω between adjacent set impedance points to achieve the desired impedance rise rate. Other desired rise rates could be achieved as well, such as by changing the dwell time to 2 seconds or using differences of 50Ω between adjacent set impedance points, for example.

Thus, the control circuit 710 could execute an impedance rate algorithm, which could be programmed into the memory of the surgical instrument 7012 or received by a surgical hub or cloud computing system. In particular, the control circuit 710 could receive a first tissue impedance point (e.g., given first set impedance point), determine a first power level of the electrosurgical energy that corresponds to the first tissue impedance point, control the generator to deliver the electrosurgical energy at the first power level, determine a second tissue impedance point, adjust the first power level to a second power level of the electrosurgical energy based on a time interval to reach the second tissue impedance point; control the generator to deliver the electrosurgical energy at the second power level. More tissue impedance points in the series of impedance points could be determined or targeted to achieve a selective impedance increase. For example, the control circuit 710 could determine a third tissue impedance point and determine the second tissue impedance point based on the third tissue impedance point and a corresponding time interval to reach the first tissue impedance point. The control circuit 710 may determine the third impedance point and associated power level after controlling the generator 4002 to deliver electrosurgical energy to reach the second impedance point.

Dwell time may also be implemented. For example, the control circuit 710 may dwell for a time before adjusting from the first to second power level and determining the third tissue impedance point. Also, for example, the control circuit may control the generator 4002 to apply power according to the following: applying a first power level to reach a first tissue impedance point; terminating, application of the first power level for a first dwell time; determining, by the control circuit, a second tissue impedance point; applying a second power level to reach the second tissue impedance point; terminating application of the second power level for a second dwell time; determining, by the control circuit, a third tissue impedance point; and applying a third power level to reach the third tissue impedance point to achieve the target impedance rise rate. The generator could further terminate application of the third power level for a third dwell time, determine a fourth tissue impedance point; and apply a fourth power level to reach the fourth tissue impedance point. As discussed above, set impedance points in the series can be determined based on prior impedance points and the time of delivering electrosurgical energy to achieve those points. Therefore, the third and fourth impedance points can be determined based on a first and second impedance point and a time to achieve them. The time to achieve the impedance points (e.g., first, second, and third points) can correspond to a predetermined coagulation time interval.

FIGS. 27A-27F are graphs and flow charts 203720, 203740, 203760, 203780, 203800, 203820, illustrating approaches to delivering energy according to power curves, in accordance with at least one aspect of the present disclosure. More details regarding such approaches may be found in U.S. Pat. No. 9,737,355 titled CONTROLLING IMPEDANCE RISE IN ELECTROSURGICAL MEDICAL DEVICES, which is hereby incorporated by reference herein in its entirety; and U.S. Patent App. Pub. No. 2018/0036065, titled METHODS AND SYSTEMS FOR ADVANCED HARMONIC ENERGY, which is hereby incorporated by reference herein in its entirety.

FIG. 27A shows one aspect of a chart 203720 showing example power curves 203726, 203728, 203730. The chart 203720 comprises an impedance x-axis 203722 denotes increasing tissue impedances from left to right. A power y-axis 203724 denotes increasing power from down to up. Each of the power curves 203726, 203728, 203730 may define a set of power levels, on the power y-axis 203724, corresponding to a plurality of potential sensed tissue impedances, in the impedance x-axis 203722. In general, power curves may take different shapes, and this is illustrated in FIG. 27A. Power curve 203726 is shown with a step-wise shape, while power curves 203728, 203730 are shown with curved shapes. It will be appreciated that power curves utilized by various aspects may take any usable continuous or non-continuous shape. The rate of power delivery or aggressiveness of a power curve may be indicated by its position on the chart 203720. For example, power curves that deliver higher power for a given tissue impedance may be considered more aggressive. Accordingly, between two power curves, the curve positioned highest on the power axis 203724 may be the more aggressive. It will be appreciated that some power curves may overlap.

The aggressiveness of two power curves may be compared according to any suitable method. For example, a first power curve may be considered more aggressive than a second power curve over a given range of potential tissue impedances if the first power curve has a higher delivered power corresponding to at least half of the range of potential tissue impedances. Also, for example, a first power curve may be considered more aggressive than a second power curve over a given range of potential tissue impedances if the area under the first curve over the range is larger than the area under the second curve over the range. Equivalently, when power curves are expressed discretely, a first power curve may be considered more aggressive than a second power curve over a given set of potential tissue impedances if the sum of the power values for the first power curve over the set of potential tissue impedances is greater than the sum of the power values for the second power curve over the set of potential tissue impedances.

Some aspects of the surgical instrument 7012 comprise a positive temperature coefficient (PTC) material positioned between one or more of the electrodes of the jaws 203562, 203564. The PTC material may have an impedance profile that remains relatively low and relatively constant until it reaches a threshold or trigger temperature, at which point the impedance of the PTC material may increase. In use, the PTC material may be placed in contact with the tissue while power is applied. The trigger temperature of the PTC material may be selected such that it corresponds to a tissue temperature indicating the completion of welding or coagulation. Accordingly, as a welding or coagulation process is completed, the temperature of the PTC material may increase, causing a corresponding increase in the impedance of the PTC material. This additional series impedance, in series with the tissue, may cause a decrease in power actually provided to the tissue 203570.

It will be appreciated that during the coagulation or welding process, tissue impedance may generally increase. In some aspects, tissue impedance may display a sudden impedance increase indicating successful coagulation. The increase may be due to physiological changes in the tissue, a PTC material reaching its trigger threshold, etc. The amount of energy that may be required to bring about the sudden impedance increase may be related to the thermal mass of the tissue 203570 being acted upon. The thermal mass of any given tissue bite, in turn, may be related to the type and amount of tissue 203570 in the bite. The PTC material could be used to determine a weld time of a surgical operation performed by the surgical instrument 7012. Also, monitoring the PTC material or other sensors 788 in the end effector 203560 may be performed by the control circuit 710 to determine a coagulation focal/focus point and the progression of the surgical treatment (e.g, cutting). Based on these determinations, the control circuit 710 can adjust a heat flux control threshold along the length of the ultrasonic blade 203564.

Various aspects may utilize this sudden increase in tissue impedance to select an appropriate power curve for a given tissue bite. For example, the generator 4012 may select and apply successively more aggressive power curves until the tissue impedance reaches an impedance threshold indicating that the sudden increase has occurred. For example, reaching the impedance threshold may indicate that coagulation is progressing appropriately with the currently applied power curve. The impedance threshold may be a tissue impedance value, a rate of change of tissue impedance, and/or a combination of impedance and rate of change. For example, the impedance threshold may be met when a certain impedance value and/or rate of change are observed. According to various aspects, different power curves may have different impedance thresholds, as described herein.

FIG. 27B shows one aspect of a process flow 203740 for applying one or more power curves to a tissue bite of the tissue 203570. Any suitable number of power curves may be used. The power curves may be successively applied in order of aggressiveness until one of the power curves drives the tissue to the impedance threshold. At step 203742, the generator 4002 may apply a first power curve. According to various aspects, the first power curve may be selected to deliver power at a relatively low rate. For example, the first power curve may be selected to avoid tissue searing with the smallest and most vulnerable expected tissue bites.

The first power curve may be applied to the tissue 203570 in any suitable manner. For example, the generator 4002 may generate a drive signal implementing the first power curve. The power curve may be implemented by modulating the power of the drive signal. The power of the drive signal may be modulated in any suitable manner. For example, the voltage and/or current of the signal may be modulated. Also, in various aspects, the drive signal may be pulsed. For example, the generator 4002 may modulate the average power by changing the frequency, pulse width, duty cycle, etc. of the drive signal. The drive signal may be provided to the electrodes of the first and second jaw members 203562, 203564.

While applying the first power curve, the generator 4002 may monitor the total energy provided to the tissue 203570. The impedance of the tissue 203570 may be compared to the impedance threshold at one or more energy thresholds. There may be any suitable number of energy thresholds, which may be selected according to any suitable methodology. For example, the energy thresholds may be selected to correspond to known points where different tissue types achieve the impedance threshold. At step 203744, the generator 4002 may determine whether the total energy delivered to the tissue 203570 has met or exceeded a first energy threshold. If the total energy has not yet reached the first energy threshold, the generator 4002 may continue to apply the first power curve at 203742.

If the total energy has reached the first energy threshold, the generator 4002 may determine whether the impedance threshold has been reached (step 203746). As described above, the impedance threshold may be a predetermined rate of impedance change (e.g., increase) a predetermined impedance, or combination of the two. If the impedance threshold is reached, the generator 4002 may continue to apply the first power curve at step 203742. For example, reaching the impedance threshold in the first power curve may indicate that the aggressiveness of the first power curve is sufficient to bring about suitable coagulation or welding.

In the event that the impedance threshold is not reached at step 203746, the generator 4002 may increment to the next most aggressive power curve at step 203748 and apply the power curve as the current power curve at 203742. In some aspects, incrementing to the next most aggressive power curve may comprise applying a multiplier to a less aggressive power curve such as, for example, the previously implemented power curve. When the next energy threshold is reached at step 203744, the generator 4002 again may determine whether the impedance threshold is reached at step 203746. If it is not reached, the generator 4002 may again increment to the next most aggressive power curve at step 203748 and deliver that power curve at step 203742.

The process flow 203740 may continue until terminated. For example, the process flow 203740 may be terminated when the impedance threshold is reached at step 203746. Upon reaching the impedance threshold, the generator 4002 may apply the then-current power curve until coagulation or welding is complete. Also, for example, the process flow 203740 may terminate upon the exhaustion of all available power curves. Any suitable number of power curves may be used. If the most aggressive power curve fails to drive the tissue to the impedance threshold, the generator 4002 may continue to apply the most aggressive power curve until the process is otherwise terminated (e.g., by a clinician or upon reaching a final energy threshold).

According to various aspects, the process flow 203740 may continue until the occurrence of a termination threshold. The termination threshold may indicate that coagulation and/or welding is complete. For example, the termination threshold may be based on one or more of tissue impedance, tissue temperature, tissue capacitance, tissue inductance, elapsed time, etc. Upon termination, the surgical instrument 7012 and/or surgical hub 5104 may generate an audible tone indicating termination. These may be a single termination threshold or, in various aspects, different power curves may have different termination thresholds. According to various aspects, different power curves may utilize different impedance thresholds. For example, the process flow 203740 may transition from a first to a second power curve if the first power curve has failed to drive the tissue to a first tissue impedance threshold and may, subsequently, shift from the second to a third power curve if the second power curve has failed to drive the tissue to a second impedance threshold. In some aspects, rather than proceeding between power curves in order, the generator 4002 may skip one or more power curves. For example, if the impedance of the tissue at the end of a power curve exceeds a skip threshold, then generator 4002, instead of proceeding to the next power curve, may skip to a more aggressive power curve (e.g., a power curve that provides more energy for a given tissue impedance).

In some aspects utilizing a pulsed drive signal, the generator 4002 may apply one or more composite load curves to the drive signal, and ultimately to the tissue. Composite load curves, like other power curves described herein, may define a level of power to be delivered to the tissue as a function of a measured tissue property or properties. Composite load curves may, additionally, define pulse characteristics, such as pulse width, in terms of the measured tissue properties (e.g., impedance, applied current, applied voltage, temperature, reflectivity, force applied to the tissue, etc.).

FIG. 27C is a chart 203760 showing power and impedance characteristics of one aspect of a drive signal that may be provided by the generator 4002 during a first mode. In FIG. 27C, impedance is indicated in the x-axis 203762 and power is indicated on the y-axis 203764. During the first mode, the generator 4002 may be configured to provide a first power threshold 203766 to the tissue while the tissue impedance is below a threshold impedance 203768 for the mode. If the impedance of the tissue exceeds the threshold impedance 203768 for the first mode, the generator 4002 may limit the provided power to a second power threshold 203770. In various aspects, the second power threshold 203770 may be less than the maximum power that the generator 4002 is configured to deliver to the tissue. In this way, the first mode may prepare the tissue 203570 for greater power application in later modes. The application period for the first mode may be any suitable value including, for example, one second. It will be appreciated that the drive signal may be pulsed during application of the first mode. For example, the first mode may be applied as a single pulse lasting the duration of the application time period for the first mode, or in multiple shorter pulses. In aspects utilizing multiple pulses in the first mode, each pulse may conform to impedance-determined limits for drive signal power, as described.

FIG. 27D is a chart 203780 showing power and impedance characteristics of one aspect of a drive signal that may be provided by the generator 4002 during a second mode. In FIG. 27D, impedance is indicated in the x-axis 203782 and power is indicated on the y-axis 203784. In the second mode, the generator 4002 provides a relatively high level of power at the lowest tissue impedances expected to be encountered. For example, in some aspects, the full power available from the generator 4002 (203786 in FIG. 27D) may be provided at tissue impedances below the threshold impedance 203790 for the second mode. Above the threshold impedance 203790, the power may be reduced below a second power threshold 203788 so as to limit the rate of impedance increase. In some aspects, the second power threshold 203788 is greater than the second power threshold 203770 of the first mode. Also, it will be appreciated that the impedance threshold 203768 of the first mode and the impedance threshold 203790 of the second mode may be equal or may take different values depending on the implementation. The application period of the second mode may be longer than that of the first mode so as to allow the provided energy to act on the tissue. For example, in some aspects, the application period of the second period is between four and five seconds. It will be appreciated that the drive signal may also be provided as a single pulse lasting the duration of the application period and/or as multiple pulses. Again, when multiple pulses are used, each pulse may conform to the impedance-determined limits for drive signal power.

FIG. 27E is a graph 203800 shows an example of a typical load curve for a generator configured to provide power to an electrosurgical system of the present disclosure. In particular, FIG. 27E provides further details of various electrical readings of the surgical instrument system undergoing the sealing procedure during surgery. The left vertical axis represents power (W) and voltage (V), the right vertical axis represents current (A), and the horizontal axis represents load impedance (Ohms). The voltage curve 203802, current curve 203804, and power curve 203806 are shown as functions of load impedance. As shown, the amount of power and voltage applied to tissue typically reaches an impassable threshold, even over ever increasing load impedances. Looked at another way, the amount of energy applied to the tissue at a surgical site has a noticeable effect only up to certain levels of load impedances, and after a certain impedance threshold, such as 175Ω, applying more or sustained power typically has little to no benefit. Graph 203800 therefore provides further detail on why exceeding the transition impedance threshold, as shown in graph 203800, generally represents the cutoff point to which power should continue to be applied.

FIG. 27F is a graph 203820 showing an example power profile of a tapered load curve concept, with additional power characteristics superimposed. In FIG. 27F, the curve 203822 as shown by the thick line represents a measure of voltage as a function of load impedance in the tissue. The curve 203824 as shown by the medium line represents a measure of calculated power applied to the tissue as a function of load impedance. The calculated power may be the measure of power that is determined by the power system of the surgical instrument 7012, while the curve 203826 as shown by the dashed line represents the actual or effective power applied to the tissue. As shown, both of these curves exhibit a power taper that is reduced in a stepwise manner. This may be caused by the power being duty cycled at different rates over time, i.e., via pulse width modulation. The curve 203828 as shown by the thin line represents a measure of current. The scale for the current is shown on the right-hand side, while the scale for power and voltage is shown on the left.

EXAMPLES

Various aspects of the subject matter described herein are set out in the following numbered examples:

Example 1

A surgical instrument comprises an end effector, an electrode, an ultrasonic transducer, a sensor coupled to a control circuit, and the control circuit coupled to the end effector. The end effector comprises: an ultrasonic blade configured to ultrasonically oscillate against tissue; and a clamp arm configured to pivot relative to the ultrasonic blade. The electrode is configured to receive electrosurgical energy from a generator and to apply the received electrosurgical energy to the end effector to weld tissue based on the generator generating a drive signal. The ultrasonic transducer is acoustically coupled to the ultrasonic blade. The ultrasonic transducer is configured to ultrasonically oscillate the ultrasonic blade in response to the drive signal. The sensor is configured to output a signal indicative of a surgical parameter to the control circuit. The control circuit is configured to: receive the sensor signal; determine a weld time of a surgical operation performed by the surgical instrument based on the sensor signal; and vary one or more of a clamp arm pressure applied by the clamp arm and a power level of the electrosurgical energy to maintain one or more of a predefined heat flux or power applied to tissue loaded in the end effector.

Example 2

The surgical instrument of Example 1, wherein the surgical parameter is one or more of tissue impedance, a natural frequency of the ultrasonic blade, temperature, and a tissue parameter.

Example 3

The surgical instrument of Examples 1 or 2, wherein the control circuit is further configured to vary one or more of the clamp arm pressure applied by the clamp arm and the power level of the electrosurgical energy based on a heat flux control threshold.

Example 4

The surgical instrument of Example 3, wherein the control circuit is further configured to adjust the heat flux control threshold along a length of the ultrasonic blade based on one or more of a coagulation focus point and a progression of a surgical cut.

Example 5

The surgical instrument of Examples 1, 2, 3, or 4, wherein the electrode comprises a plurality of electrodes positioned longitudinally to generate a constant current density.

Example 6

The surgical instrument of Example 5, wherein the control circuit is further configured to energize the plurality of electrodes sequentially to generate a first current density in a proximal portion of the plurality of electrodes and a second current density in a distal portion of the plurality of electrodes, and wherein the first and second current density are equal.

Example 7

The surgical instrument of Example 5, further comprising the generator configured to deliver the electrosurgical energy to the end effector, wherein the control circuit is further configured to control the generator to energize the plurality of electrodes by providing a first power level to a first portion of the plurality of electrodes and a second power level to a second portion of the plurality of electrodes, and wherein the first power level is lower than the second power level.

Example 8

The surgical instrument of Examples 1, 2, 3, 4, 5, 6, or 7 wherein the clamp arm is an offset clamp arm and control circuit is further configured to increase the clamp arm pressure based on the sensor signal.

Example 9

A surgical system comprising a surgical hub configured to receive an impedance rate algorithm transmitted from a cloud computing system and a surgical instrument communicatively coupled to the surgical hub. The surgical hub is communicatively coupled to the cloud computing system. The surgical instrument comprises an end effector, electrode, ultrasonic transducer, and a control circuit. The end effector comprises an ultrasonic blade configured to ultrasonically oscillate against tissue; and a clamp arm configured to pivot relative to the ultrasonic blade. The electrode is configured to receive electrosurgical energy from a generator and apply the received electrosurgical energy to the end effector to weld tissue based on the generator generating a drive signal. The ultrasonic transducer is acoustically coupled to the ultrasonic blade. The ultrasonic transducer is configured to ultrasonically oscillate the ultrasonic blade in response to the drive signal. The control circuit is coupled to the end effector. The control circuit is configured to perform the impedance rate algorithm to: receive a first tissue impedance point; determine a first power level of the electrosurgical energy that corresponds to the first tissue impedance point; control the generator to deliver the electrosurgical energy at the first power level; determine a second tissue impedance point; adjust the first power level to a second power level of the electrosurgical energy based on a time interval to reach the second tissue impedance point; and control the generator to deliver the electrosurgical energy at the second power level.

Example 10

The surgical system of Example 9, wherein the control circuit is configured to perform the impedance rate algorithm to further determine a third tissue impedance point; and determine the second tissue impedance point based on the third tissue impedance point and a corresponding time interval to reach the first tissue impedance point.

Example 11

The surgical system of Example 10, wherein the control circuit is configured to perform the impedance rate algorithm to further determine the third tissue impedance point and a third power level of the electrosurgical energy corresponding to the third tissue impedance point upon controlling the generator to deliver the electrosurgical energy at the second power level to reach the second tissue impedance point.

Example 12

The surgical system of Example 11, wherein the control circuit is configured to perform the impedance rate algorithm to further adjust the third tissue impedance point based on an overall tissue impedance level and the time interval to reach the second tissue impedance point.

Example 13

The surgical system of Example 10, wherein the control circuit is configured to perform the impedance rate algorithm to further determine a dwell time and control the generator to deliver the electrosurgical energy at the first power level for the dwell time prior to adjusting the first power level to the second power level of the electrosurgical energy and determining the third tissue impedance point.

Example 14

The surgical system of Examples 9, 10, 11, 12, or 13 wherein the electrode comprises a plurality of electrode segments positioned longitudinally to generate a constant current density.

Example 15

The surgical system of Example 14, wherein the control circuit is configured to perform the impedance rate algorithm to further energize the plurality of electrode segments based on a progressive closure stroke of the clamp arm.

Example 16

A method of using a surgical instrument to deliver electrosurgical energy according to a target impedance rise rate, wherein the surgical instrument comprises an end effector, a generator, an electrode configured to deliver the electrosurgical energy to the end effector, an ultrasonic transducer acoustically coupled to the ultrasonic blade, and a control circuit coupled to the end effector. The generator is configured to deliver electrosurgical energy to the end effector based on generating a drive signal. The ultrasonic transducer is configured to ultrasonically oscillate the ultrasonic blade in response to the drive signal. The end effector comprises an ultrasonic blade configured to ultrasonically oscillate against tissue; and a clamp arm configured to pivot relative to the ultrasonic blade. The method comprises: controlling, by the control circuit, the generator to apply power according to a tissue impedance algorithm comprising the steps of: applying, by the generator, a first power level to reach a first tissue impedance point; terminating, by the generator, application of the first power level for a first dwell time; determining, by the control circuit, a second tissue impedance point; applying, by the generator, a second power level to reach the second tissue impedance point; terminating, by the generator, application of the second power level for a second dwell time; determining, by the control circuit, a third tissue impedance point; and applying, by the generator, a third power level to reach the third tissue impedance point to achieve the target impedance rise rate.

Example 17

The method of Example 16, further comprising: terminating, by the generator, application of the third power level for a third dwell time; determining, by the control circuit, a fourth tissue impedance point; and applying, by the generator, a fourth power level to reach the fourth tissue impedance point.

Example 18

The method of Example 17, wherein the third and fourth tissue impedance point are determined based on one or more of first and second tissue impedance point and a time to achieve each of the first and second tissue impedance point.

Example 19

The method of Examples 16, 17, or 18, wherein a time to achieve the first, second, and third tissue impedance point corresponds to a predetermined coagulation time interval.

Example 20

The method of Examples 16, 17, 18, or 19, wherein the electrode comprises a plurality of electrode segments positioned longitudinally to generate a constant current density.

While several forms have been illustrated and described, it is not the intention of Applicant to restrict or limit the scope of the appended claims to such detail. Numerous modifications, variations, changes, substitutions, combinations, and equivalents to those forms may be implemented and will occur to those skilled in the art without departing from the scope of the present disclosure. Moreover, the structure of each element associated with the described forms can be alternatively described as a means for providing the function performed by the element. Also, where materials are disclosed for certain components, other materials may be used. It is therefore to be understood that the foregoing description and the appended claims are intended to cover all such modifications, combinations, and variations as falling within the scope of the disclosed forms. The appended claims are intended to cover all such modifications, variations, changes, substitutions, modifications, and equivalents.

The foregoing detailed description has set forth various forms of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, and/or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. Those skilled in the art will recognize that some aspects of the forms disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as one or more program products in a variety of forms, and that an illustrative form of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution.

Instructions used to program logic to perform various disclosed aspects can be stored within a memory in the system, such as dynamic random access memory (DRAM), cache, flash memory, or other storage. Furthermore, the instructions can be distributed via a network or by way of other computer readable media. Thus a machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer), but is not limited to, floppy diskettes, optical disks, compact disc, read-only memory (CD-ROMs), and magneto-optical disks, read-only memory (ROMs), random access memory (RAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic or optical cards, flash memory, or a tangible, machine-readable storage used in the transmission of information over the Internet via electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Accordingly, the non-transitory computer-readable medium includes any type of tangible machine-readable medium suitable for storing or transmitting electronic instructions or information in a form readable by a machine (e.g., a computer).

As used in any aspect herein, the term “control circuit” may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor including one or more individual instruction processing cores, processing unit, processor, microcontroller, microcontroller unit, controller, digital signal processor (DSP), programmable logic device (PLD), programmable logic array (PLA), or field programmable gate array (FPGA)), state machine circuitry, firmware that stores instructions executed by programmable circuitry, and any combination thereof. The control circuit may, collectively or individually, be embodied as circuitry that forms part of a larger system, for example, an integrated circuit (IC), an application-specific integrated circuit (ASIC), a system on-chip (SoC), desktop computers, laptop computers, tablet computers, servers, smart phones, etc. Accordingly, as used herein “control circuit” includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program which at least partially carries out processes and/or devices described herein, or a microprocessor configured by a computer program which at least partially carries out processes and/or devices described herein), electrical circuitry forming a memory device (e.g., forms of random access memory), and/or electrical circuitry forming a communications device (e.g., a modem, communications switch, or optical-electrical equipment). Those having skill in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof.

As used in any aspect herein, the term “logic” may refer to an app, software, firmware and/or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets and/or data recorded on non-transitory computer readable storage medium. Firmware may be embodied as code, instructions or instruction sets and/or data that are hard-coded (e.g., nonvolatile) in memory devices.

As used in any aspect herein, the terms “component,” “system,” “module” and the like can refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution.

As used in any aspect herein, an “algorithm” refers to a self-consistent sequence of steps leading to a desired result, where a “step” refers to a manipulation of physical quantities and/or logic states which may, though need not necessarily, take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It is common usage to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and/or states.

A network may include a packet switched network. The communication devices may be capable of communicating with each other using a selected packet switched network communications protocol. One example communications protocol may include an Ethernet communications protocol which may be capable permitting communication using a Transmission Control Protocol/Internet Protocol (TCP/IP). The Ethernet protocol may comply or be compatible with the Ethernet standard published by the Institute of Electrical and Electronics Engineers (IEEE) titled “IEEE 802.3 Standard”, published in December, 2008 and/or later versions of this standard. Alternatively or additionally, the communication devices may be capable of communicating with each other using an X.25 communications protocol. The X.25 communications protocol may comply or be compatible with a standard promulgated by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T). Alternatively or additionally, the communication devices may be capable of communicating with each other using a frame relay communications protocol. The frame relay communications protocol may comply or be compatible with a standard promulgated by Consultative Committee for International Telegraph and Telephone (CCITT) and/or the American National Standards Institute (ANSI). Alternatively or additionally, the transceivers may be capable of communicating with each other using an Asynchronous Transfer Mode (ATM) communications protocol. The ATM communications protocol may comply or be compatible with an ATM standard published by the ATM Forum titled “ATM-MPLS Network Interworking 2.0” published August 2001, and/or later versions of this standard. Of course, different and/or after-developed connection-oriented network communication protocols are equally contemplated herein.

Unless specifically stated otherwise as apparent from the foregoing disclosure, it is appreciated that, throughout the foregoing disclosure, discussions using terms such as “processing,” “computing,” “calculating,” “determining,” “displaying,” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.

One or more components may be referred to herein as “configured to,” “configurable to,” “operable/operative to,” “adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Those skilled in the art will recognize that “configured to” can generally encompass active-state components and/or inactive-state components and/or standby-state components, unless context requires otherwise.

The terms “proximal” and “distal” are used herein with reference to a clinician manipulating the handle portion of the surgical instrument. The term “proximal” refers to the portion closest to the clinician and the term “distal” refers to the portion located away from the clinician. It will be further appreciated that, for convenience and clarity, spatial terms such as “vertical”, “horizontal”, “up”, and “down” may be used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and/or absolute.

Those skilled in the art will recognize that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to claims containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that typically a disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms unless context dictates otherwise. For example, the phrase “A or B” will be typically understood to include the possibilities of “A” or “B” or “A and B.”

With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flow diagrams are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those which are illustrated, or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise.

It is worthy to note that any reference to “one aspect,” “an aspect,” “an exemplification,” “one exemplification,” and the like means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, appearances of the phrases “in one aspect,” “in an aspect,” “in an exemplification,” and “in one exemplification” in various places throughout the specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more aspects.

Any patent application, patent, non-patent publication, or other disclosure material referred to in this specification and/or listed in any Application Data Sheet is incorporated by reference herein, to the extent that the incorporated materials is not inconsistent herewith. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

In summary, numerous benefits have been described which result from employing the concepts described herein. The foregoing description of the one or more forms has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more forms were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the various forms and with various modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope. 

The invention claimed is:
 1. A surgical instrument comprising: an end effector comprising: an ultrasonic blade configured to ultrasonically oscillate against tissue; and a clamp arm configured to pivot relative to the ultrasonic blade; an electrode configured to receive electrosurgical energy from a generator and apply the received electrosurgical energy to the end effector to weld tissue based on the generator generating a drive signal; an ultrasonic transducer acoustically coupled to the ultrasonic blade, the ultrasonic transducer configured to ultrasonically oscillate the ultrasonic blade in response to the drive signal; a sensor coupled to a control circuit, wherein the sensor is configured to output a signal indicative of a surgical parameter to the control circuit; and the control circuit coupled to the end effector, wherein the control circuit is configured to: receive the sensor signal; determine a cutting and coagulation focal point along the length of the ultrasonic blade, wherein the cutting and coagulation focal point shifts between the proximal and distal end of the ultrasonic blade; determine a weld time of a surgical operation performed by the surgical instrument based on the sensor signal; and vary one or more of a clamp arm pressure applied by the clamp arm and a power level of the electrosurgical energy to maintain one or more of a predefined heat flux or power applied to tissue loaded in the end effector, wherein the clamp arm pressure and power level are based in part on the location of the cutting and coagulation focal point, and wherein the predefined heat flux is constant along the length of the ultrasonic blade.
 2. The surgical instrument of claim 1, wherein the surgical parameter is one or more of tissue impedance, a natural frequency of the ultrasonic blade, temperature, and a tissue parameter.
 3. The surgical instrument of claim 1, wherein the control circuit is further configured to vary one or more of the clamp arm pressure applied by the clamp arm and the power level of the electrosurgical energy based on a heat flux control threshold.
 4. The surgical instrument of claim 3, wherein the control circuit is further configured to adjust the heat flux control threshold along a length of the ultrasonic blade based on one or more of a coagulation focus point and a progression of a surgical cut.
 5. The surgical instrument of claim 1, wherein the electrode comprises a plurality of electrodes positioned longitudinally to generate a constant current density.
 6. The surgical instrument of claim 5, wherein the control circuit is further configured to energize the plurality of electrodes sequentially to generate a first current density in a proximal portion of the plurality of electrodes and a second current density in a distal portion of the plurality of electrodes, and wherein the first and second current densities are equal.
 7. The surgical instrument of claim 5, further comprising the generator configured to deliver the electrosurgical energy to the end effector, wherein the control circuit is further configured to control the generator to energize the plurality of electrodes by providing a first power level to a first portion of the plurality of electrodes and a second power level to a second portion of the plurality of electrodes, and wherein the first power level is lower than the second power level.
 8. The surgical instrument of claim 1, wherein the clamp arm is an offset clamp arm and the control circuit is further configured to increase the clamp arm pressure based on the sensor signal.
 9. A surgical system comprising: a surgical hub configured to receive an impedance rate algorithm transmitted from a cloud computing system, wherein the surgical hub is communicatively coupled to the cloud computing system; and a surgical instrument communicatively coupled to the surgical hub, wherein the surgical instrument comprises: an end effector comprising: an ultrasonic blade configured to ultrasonically oscillate against tissue; and a clamp arm configured to pivot relative to the ultrasonic blade; an electrode configured to receive electrosurgical energy from a generator and apply the received electrosurgical energy to the end effector to weld tissue based on the generator generating a drive signal; an ultrasonic transducer acoustically coupled to the ultrasonic blade, the ultrasonic transducer configured to ultrasonically oscillate the ultrasonic blade in response to the drive signal; a control circuit coupled to the end effector, wherein the control circuit is configured to perform the impedance rate algorithm to: receive a first tissue impedance point of a series of sequential impedance points; determine a first power level of the electrosurgical energy that corresponds to the first tissue impedance point; control the generator to deliver the electrosurgical energy at the first power level; determine a second tissue impedance point of the series of sequential impedance points; adjust the first power level to a second power level of the electrosurgical energy based on a time interval to reach the second tissue impedance point, where the adjustment from the first power level to the second power level is determined based on the time interval to reach the second tissue impedance point and the second power level to mimic a predicted impedance rise corresponding to the time interval; and control the generator to deliver the electrosurgical energy at the second power level.
 10. The surgical system of claim 9, wherein the control circuit is configured to perform the impedance rate algorithm to further: determine a third tissue impedance point of the series of sequential impedance points; and determine the second tissue impedance point based on the third tissue impedance point and a corresponding time interval to reach the first tissue impedance point.
 11. The surgical system of claim 10, wherein the control circuit is configured to perform the impedance rate algorithm to further recalculate the third tissue impedance point and determine a third power level of the electrosurgical energy corresponding to the third tissue impedance point upon controlling the generator to deliver the electrosurgical energy at the second power level to reach the second tissue impedance point.
 12. The surgical system of claim 11, wherein the control circuit is configured to perform the impedance rate algorithm to further adjust the third tissue impedance point based on an overall tissue impedance level and the time interval to reach the second tissue impedance point.
 13. The surgical system of claim 10, wherein the control circuit is configured to perform the impedance rate algorithm to further determine a dwell time and control the generator to deliver the electrosurgical energy at the first power level for the dwell time prior to adjusting the first power level to the second power level of the electrosurgical energy and determining the third tissue impedance point.
 14. The surgical system of claim 9, wherein the electrode comprises a plurality of electrode segments positioned longitudinally to generate a constant current density.
 15. The surgical system of claim 14, wherein the control circuit is configured to perform the impedance rate algorithm to further energize the plurality of electrode segments based on a progressive closure stroke of the clamp arm.
 16. A method of using a surgical instrument to deliver electrosurgical energy according to a target impedance rise rate, wherein the surgical instrument comprises: an end effector comprising: an ultrasonic blade configured to ultrasonically oscillate against tissue; and a clamp arm configured to pivot relative to the ultrasonic blade; a generator configured to deliver electrosurgical energy to the end effector based on generating a drive signal; an electrode configured to deliver the electrosurgical energy to the end effector; an ultrasonic transducer acoustically coupled to the ultrasonic blade, the ultrasonic transducer configured to ultrasonically oscillate the ultrasonic blade in response to the drive signal generated by the generator; and a control circuit coupled to the end effector and wherein the method comprises: controlling, by the control circuit, the generator to apply power according to a tissue impedance algorithm, wherein the tissue impedance algorithm is configured to achieve a constant heat flux by adjusting power over a series of sequential impedance points, comprising the steps of: applying, by the generator, a first power level to reach a first tissue impedance point of the series of sequential impedance points; terminating, by the generator, application of the first power level for a first dwell time, wherein power is not applied during the first dwell time, and wherein the first power level is determined based on the first dwell time; determining, by the control circuit, a second tissue impedance point of the series of sequential impedance points: applying, by the generator, a second power level to reach the second tissue impedance point; terminating, by the generator, application of the second power level for a second dwell time, wherein power is not applied during the second dwell time, and wherein the second power level is determined based on the second dwell time; determining, by the control circuit, a third tissue impedance point of the series of sequential impedance points; and applying, by the generator, a third power level to reach the third tissue impedance point to achieve the target impedance rise rate.
 17. The method of claim 16, further comprising: terminating, by the generator, application of the third power level for a third dwell time, wherein power is not applied during the third dwell time, and wherein the third power level is determined based on the third dwell time; determining, by the control circuit, a fourth tissue impedance point of the series of sequential impedance points; and applying, by the generator, a fourth power level to reach the fourth tissue impedance point.
 18. The method of claim 17, wherein the third and fourth tissue impedance points are determined based on one or more of the first and second tissue impedance points and a time to achieve each of the first and second tissue impedance point.
 19. The method of claim 16, wherein a time to achieve the first, second, and third tissue impedance points corresponds to a predetermined coagulation time interval.
 20. The method of claim 16, wherein the electrode comprises a plurality of electrode segments positioned longitudinally to generate a constant current density. 